GeoSci.xyz GWB Lectures, 4 Feb 2020

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From YouTube: 2020 02 04 Day2 Part1 Background2

Description

In this lecture we continue presenting the fundamentals of the DC resistivity method. Jupyter notebook based apps are used to learn about this method.

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On this, this slide here.

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Demands on agenda I was a little bit.

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We'll do first, a review for James one.

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My review and Obama and.

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Then we'll start soundings the foundation sign.

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Mg and our main yeah.

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They will install the apps.

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You know application install about me how.

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Many people have been able to install the apps, so banana installed.

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Only got a minute, please.

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Raise your hands is Emma, gonna know which one the anaconda and go through to install the apps.

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And Devon Cowan is here today: Devon stand up.

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Is very tall, Yemen was very sick. Yesterday.

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Maybe better we're going to do two apps today, a two-layer and a three layer sounding the neons are abnegation.

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Nicole's Obama telephone and watching I have Negishi Antone right. You'll have you'll.

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Have opportunities to work with the apps and answer questions in.

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All I am a better lipid, Alawi, Oh, yummy and.

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We'll introduce you further to the case history and where our goal is to see if we can get communication on the cakes history.

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Case history, not a quarter cases reach or not. It's receive mr. Matano made like this one hmm Dorothy Cheney anubians, there's a montero be acknowledging our gonna. Do target army.

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Then we will start with the field equipment to talk about the field equipment and the data acquisition and enough.

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Salsa foods at all female, oh.

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Man, you know, keep topping the new shop. We have this without mr. tomorrow.

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Morning we will take the clip equipment to the park and acquire some data warning.

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Some of them have a net time for me, a fine sentiment other than that Bob. You know.

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So I would like now to briefly go through some of the slides that Kevin said yesterday, just to refresh your mind and I, like the basic principles that we're interested in when.

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They got Kevin Doug want a slice.

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So Kevin talked about the soils in the background, and here is the image that we will work with throughout the course with the upper played backward or the upper aquifer and a deeper.

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Afterbirth with Iman eyes on our movie nano2 again, we don't have to vote on it. You go out to the phones I'm going on. You know that song. You know the house, no, not having done Mama's early, you might set up a minute. I may walk down the what I wrong.

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So the hip, the aquifers, have different character characteristics. They depend upon what what the soils are. So there could be fine, grained soils up towards the surface or they could be coarser granite, rocks that have water in at a depth. I'm.

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Am using you hmm you, when the island, your bet, no I did not bomb I've got it I miss about New York and what I told you so they talk.

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The important quantity for hydrogen physics was the electrical conductivity or the hydraulic, conductivity K, which tells you how easy it is for water to flow.

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Through a rock, so hydraulic boom docks it with G 0 kt. What you think I go under up. You know thing: women love C night. Now the.

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Important physical property for geophysics is electrical conductivity or the reciprocal resistivity.

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Not totally me.

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But never that.

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Easy there check out.

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The contact ability or conductivity thermal resistivity- oh no, no we're.

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Going to talk about resistivity in all meters, the conductivity is the reciprocal of that.

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Inverse inverse.

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So different rocks have different conductivity and the conductivity depends upon the rock type. The porosity never Kevin talked about how much airspace is in vain rock material, how the pores are connected and what the nature of that fluid is.

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Yes, timi pani, poni or not, but that's our job. Yes, I want eleventy man you're all right. Oh the blob of the year when a good example and email below I founded a ga who ate the ba da ba ba ba I rode a conductivity down. What about it.

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So resistivity that we're interested in is you know, maybe ten to a thousand ohm meters that contains fresh water. It also contains clays and it contains our Granite's dhwaja.

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To say only done it the tongue, the child walks in without open, oh hey, Molly, bye, bye, my name's of your daddy when I'm lying them upon oh I'm, a genie to the power 9 and granite level, and initially the edema about shinojima, not going on so.

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We want to find the electrical resistivity and we're going to do a geophysical survey. Every geophysical survey requires a source put energy into the ground, so.

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There are the resistivity shallow measure and a druggie. You know permeable identity, Selena Gomez, another so spot so snowman, so sturdy enough potato. What is the middle? Yes- and this is the physical.

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Property role that we're looking for and then there will be a response that we can't.

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Enter a name holidays, yeah, yeah, yeah, la foto de demain, and that feel Amara determinant another one on.

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The DC resistivity experiment is characterized by this. We have different units. An upper layer here may be something just resist, something that has low resistivity here to.

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Dedes, a number of the content, don't really focus on your meter for now for some anti resistivity that you kidding an alcoholic uttering that I've been.

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A volunteer or a student today.

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Yeah yeah perpendicular to our downline. You are opposed to sticking together so.

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We want to find this so we're going to set up an experiment, we're going to take a battery generator and we're going to put one end up here and the other end here. But two group stakes into the ground connect them up with a battery.

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So when the work will chime a tiger a little battery 19-man, take it right out sama how much you got when.

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We do that currents flow through the earth, they throw around objects that are resistive and they tend to flow through objects that have low resistivity. So.

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Resistivity in the block step on it, yeah I stopped. You know that what I have it Sheetal enough resistive, the young innocent victims teasing, doesn't matter because any time I even when then most our resistivity ro, you don't see when it goes out a.

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Property that happens when current tries to flow through a rod. The current has to stay constant, and this requires that there's charges that fill build.

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Up so duan zong-de jump to accelerate the SSD down darling dmg, honorable geometry, as a matter of charges.

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Minus me, yeah, plus max, and each charge gives rise to an electric potential at the surface because of Coulomb's law.

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Who comes to law, yeah and a blogger up yeah that woman? This is something.

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So that's the basic experiment and when we think about our geometry here for aquifers, it's the same, the same thing: here's a layered earth with a conductive aquifer in it.

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Saddam through elementary yeah, theatrical example or daughter.you nipple.

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It has a Hamas.

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And necesito on an echo file, she may be mom when.

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We put the current in this.

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Is he under taillight there come on it.

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Flows through the ground, depending upon how the resistivity is so.

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Resistors DVD 4 mu, DP obey the rock blue C dominant missus simulator, our Michael's I'm Carla. These.

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Lines are the current lines, and this is going to will see this in the first app, the smaller in.

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General need the muslim-american monomers I. Do you sec, don't see their women? This.

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Also generates charges at the top and the bottom of the layer.

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Well, by now, by machine a charges in there muffled Ali Ben those.

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Charges give rise to an electric.

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Potential, that's.

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Measured or the exists.

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At the surface, let electric potential mu t you know of Eddie: oh, they make Tommy another one Kavya Valley men. We.

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Can measure the potential difference between two points so.

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What I call a machine of potential yet China is over nervous. That's called delta v delta v of.

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Domain and then we can convert that measurement to an apparent resistivity with this formula.

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So a formula a general apparent resistivity, which our young fellow so.

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Will see this particular image much throughout the.

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Course so the generality thou shalt keep only will better off then, and the Coulomb are separate. Yeah.

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We will work continually through our seventh step procedure, which set up and the properties the.

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Neon Joe do a lot of time. I measure of the brick wall, Cano coupon, are things you know. We go men.

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No some made up some people, a simple movie.

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Bill already roasted Obama set up. She may it's a broker. That I will talk about your main properties about darkness, Roger, the young men. We collect the peel data, Trophy winners, a military campaign. We get.

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Some data that we.

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Measure right, $9.00, a dinner yamame. We.

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Process the data to get an image.

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So int Jerry, whether a poem to Longbourn on your community louder or process snowman.

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We interpret the image in terms of geology, so.

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Giorgia in yah-yah-yah-yah gonna be a gala yesterday, a subtotal interpreted of man and then.

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We have a synthesis asking: how well did we do.

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So general, not to us in the sticks that are plotting our military. How be able talk that? Let us say that we have.

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A case history that we're going to ask you to work on the mob case.

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History, my lookbook for case history season highs today and.

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This case, history is a local site where a vertical electric sounding was done. The.

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Case history, design of new people coming in and looked at Madaba, not okay, be the hot weather. Oh damn bro la-da-da new young. Your case is rechargeable man and.

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We'll take will go all the way through those seven steps through the course of the of the training period and have people work with us to finalize this case. History enough.

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Quad the children in thailand. Imagine Madhavi understand that, but the local network, instead they sent me the same Ogami, certainly saladin cases units at the right now so luminous objects. You love.

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Neighs balance.

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Then I'm now going to.

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So I would not like to start our section on soundings. You.

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Can make it something especially about stopping.

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Here's our DC resistivity survey, the source, the resistivity that we're looking for and the data that we're going to collect.

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So that off look I'm, a homeowner, solstice or a poem, a diamond. If I may being go shopping today, resistivity Rho.

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So we're going to go through the basic experiment, we're going to those.

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Are a Jenkins huh that's a bit okay, but.

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Look at the current charges, the potentials currents.

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The duchess de madera.

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Parent resistivities, resistivity and we'll do some hands-on work and look at sound because up resonators I'm down there. So here's our our basic experiment, which.

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We've just seen that's a chicken experiment or Nelson. That's a and.

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Now we're going to look at our first, but first before we do that. I want to first of all talk about something called open source.

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Java application, Mazal hot dogs, you know phenomenon, give me money open source, 300, ordinay, you've got somebody how.

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Many people here know what we mean by open source.

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Open source know your name.

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Yeah, open source is anything that is available on on the Internet. That is just yours to use and you can access it and use it freely. Open.

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So that's our internet. Oh my gosh.

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That includes computer software. It can includes resource information.

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Anything falls into that category, so.

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Any open source state country Amazon fire bottle missing from internet the moment economic software antenna.

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Importantly, open source also gives you an opportunity to contribute so our car would we develop something. It's open source our car could contribute. I could contribute, we, everybody could work together.

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Yeah, nothing Oh pencils, not you know how take me.

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In my nightmare cool, a yo-yo, you.

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Don't know how well they.

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So up up here there is a site: HTTP Jesus, I, dot, X Y Z. If you have internet available, do you want to try that particular site.

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International Minister eyesight entity.

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You should see you should see something that looks like this. How many people are able, how many people have internet connections and are able to go to this site? I.

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Expect that when 0 DB admin Yoshi a ok.

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Successful: ah okay- let's listen up, others can try later, but let me walk you through this site and in particular.

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Is this this can be, but this is our window to development of open source d'argent.

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Open source corner inaudible, generic or not, there's.

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A number of elements on here I'm only going to go through a couple. This first one I think, would be a very much interest to you win-win. It's called GPG geophysics for practicing geo scientists puzzled.

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The unica, a young thing, is not that dominate. You have to pilot gbg, look all about it and.

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When you click on that it takes you to this page, it's got a table of things that are useful for telling geologists or engineers about what geophysics yeah.

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We were late on a buffalo post on you, olynyk or not. I might be mushy days, Oh Polly, listen, my boundary comes in the eyes, are wrong. People need wonderful authorities or engineer or TV without national savings.

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Little Yama Yamaha so.

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One of the things here is TC resistivity, others also ground-penetrating radar, seismic magnetics physical properties. We use this as our tax for engineers and geologists. It's art, it's a textbook.

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Nodular my column name I'm, not far about these the resistivity net bottom of nine, powerful right out your balloon, assorted or focus on it. I'm, throwing a party house.

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So we can go into this more later, but it's something that for geologists or engineers who want to know something about geophysics and have these different types of surveys. This is a good resource, donto.

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Became dominant in my vanity in Scenario dress, we will have nationally.

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There's others on here. This is electromagnetic geophysics. We gave a course around the world, the disc lectures that use material from here so.

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The xmi PM's already had some a.

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Your physics that looking around a yes it is it my life, meaning Bala, so that I, you thought we don't. Things are intimate, don't know how deep are a poet, Emily, DC.

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Resistivity is a very special form of electromagnetics the DC resistivity. The current is constant current.

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Dc2 'god constant to this well beyond. We've got the resistivity name, dominion, telephones and is a man named naples answer the gate was special today, novena volatilities, our DC resistivity done anything in.

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Electromagnetics the current changes with time- and it gives you a different way of sensing the earth sensing sending information to.

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The ER so electromagnetic shout up shop of domination, a young man in Hazzard walk when abilities in ever to walk what I'm being.

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Tied everything today.

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Has anybody here heard of airborne electromagnetics airborne airplane with.

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Electromagnetic.

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You put, you have.

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Anybody has anybody heard of that table. Do you.

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You use that in in Myanmar for X mineral exploration or groundwater, hey.

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Honey boy: the idea would be do something.

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We're talking about electrical resistivity and geese, we're using DC resistivity, but this region in here electromagnetics is also sensitive to the resistivity and there's a very powerful way of getting more information out about the resistivity electromagnetic.

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And looking dull a CD single dope, you know it's a diamond, resistivity, Mazzone electromagnetic call, a resistivity number, let's step it up, you let our little yard, though.

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Generate simulated responses from physical surveys, we need to compute do a lot of computing to Khmer t'what. The fields are going to be go ahead. Yes, I'll.

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Rephrase so that you got about the abundance of an actor on TV Thank You Danielle. Are they hiring, but there are Computing's of impurity applause, yeah I process.

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Dc region Stephanie we're going to put a current in here: here's our battery, so here's a here's B. The current is going to flow through there, okay and we want to compute what the potentials are. At the surface.

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Community mines- I, don't know eight white in it might be by my tail. I met several yes at the man. She dumped something. Okay, so I need about see their potential. Yet oh, that was Sharma. No, so.

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How do we, how do we compute that another, a balloon, that's Amalia, we know we need to know what the basic equations are. So.

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Good supporters are our equation or people who are so.

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If I wrote the following.

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Smaller, never up the following: yep.

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Something you got attitude about.

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Does anybody recognize what that is not.

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Violence or being ironic do.

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You know what the upside down triangle is a that's.

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Delta but it's upside.

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Know do you take this?

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Do you know what this is? I talked up, I dot, yeah, it's a dot. That dot is very important.

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It's a dot product, so it's a very special mathematical symbol that calls for a particular operation just the same as this is a mathematical symbol that calls for an operation so.

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I have an operation to donate, being indicted. Watch things happen, you got about it. Okay,.

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This this is how a physicist understands what is happening in the DC resistivity experiment. He has to solve this equation, but.

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Humans have a business shouldn't, both oh sorry, positioning, miss Athena. She needs out of the house, they will be able to disperse. They are upon our resistivity. We will double the ricotta in.

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One dimension for later: we just divide this up into different resistivities and layer thicknesses and then try to solve this.

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Problem so I imagine earlier today, via a relay our goal of today resisting people of she'd Israel people to look deep in the language she showers in.

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Two dimensions: we need a different structure, it's called a mesh that divides the earth up into many different cells, each of which has got its own resistivity.

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How much I resisted it luxurious without that white boy? You don't like see that neat our dilemma today. So.

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In one dimension, two dimensions: three dimensions: we solve this equation and we have different structures for what the how we represent the earth so.

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I equation would Photoshop go Bureau of Education viloma. They do the 3d one. The element about your name, Miroslava, no idea who that was or the equation.

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We're not we're not going to do any of this. This is all math. This is scientific computing.

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Diane I, don't know, Bob uh no I didn't have the Monterey would think that needs a day things Holly or not, but.

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None of the results that you are going to see today and the rest of the week could be done without scientific computing and without being able to solve this system.

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Okay, that nothing on earth- or indeed you know, I- have both undefeated and send out a pleasurable hope. I don't die anyhow, you know she says I'm value, we're never gonna, know I'm, happy yeah. So.

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How do we, how do we do this, and where is this done? We.

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Have any higher on the judge, have an epilogue of no homily is wrong. There's.

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Another box here called simpang of.

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Course, impact listen, Dorothy loves to push evil in that simulation.

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And parameter estimation in geophysics armies.

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Parameter yeah so.

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You'll see the word cippec coming many times throughout the course, because you have to load stuff from synthetic to get your apps to run so app.

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Stable or the de facto will dressing is impacted are generally and then the now.

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Shama, don't you step back without talk to any of the.

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Simple is the mathematical well, the computing structure it works with Python. I thought-.

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Loja man lived over the things. huh I think my mother does.

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Anybody here do any programming and do they do it in Python.

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Yeah, does anybody.

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Program write the program here initially Python program. You didn't.

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Who has heard of Python I thought without 9:1.

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Python is a programming language like C or Fortran or C++. Oh.

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Are all different languages for computing.

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I ain't by Python, Emma's I wrote the computing at.

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Passing I am upon.

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Just just anybody here right computing code does any ask anybody. Does anybody write computer code to manipulate numbers.

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In tab, double threat come to join everybody by.

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Not one-on-one, sorry.

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Like that, well,.

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Yeah computing, maybe you've got a time series, a sequence of numbers, and maybe you want to do something with that add them together, multiply them by something.

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The the main thing to understand here, I think this is this- is conceptually important- is that everything we're going to show you now for the rest of the week requires significant mathematical computations, which are carried out in simpe.

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We are going to welcome.

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Significant lot we're going to everything that we do everything that we do requires a lot of assuming you have a lot of computer work to get the results so.

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The reality a couple EE.

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Intendant, but for this we don't think you got it. Oh no.

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Computer does all the work. What we have done is taken problems that involve computing and made them into apps. That you can still answer, ask questions and get answers, but you don't see all of the underlying computer software that is required to run that.

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So what we're going to do is to provide you some way of Sophia of carrying out these problems, but without you actually being involved in the computations.

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For the mutations of the good, certain Molino mallamma been able to look our business with an automatic software you got, it did.

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I until I met or the result, Veronica.

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Box on here is GSI courses. Doctor provides.

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Our alternator dunya hangzhou science.

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On this or equipped lms again limousine, it takes you to geosite courses, and my courses table and I am in a man. So here's the upcoming course February 3rd 21 M.

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Odds are up, I read, know your name I, don't step on I said uh that's that to.

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You I'm a polyester off.

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I didn't allow me Josh.

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Might recognize this course I. Don't have you written anything now, maybe.

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So there's course material here. I'm odds are, of course,.

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Math Oh neck material, so.

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If you click on course, material.

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So right now, we've got course material, introduction, sounding or background soundings if I clicked on any of these.

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These are actually going to be the slides that I'm talking about tonight.

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My material sort of they me the lumpy with the anatomy, the.

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Other thing that's going to be important for today is there's going to be questions on the apps I.

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Application, my Baba ominous, you know maybe what if I'll I'm gonna tell you about it yeah they got now.

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I believe they're going to be provided in part copy, their big photo coffee, but they can also be found here.

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If I click on here then here is now, these are now the questions that we're going to ask you to do for the first app the.

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Monza application that my love, let's.

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Resume met a boy named Giovanni.

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Dario Argento photo coming up, you know, be Mahara, be monogamy. The software.

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Male who's winner, to be honest about the.

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Case history, that I was talking about your case history back, okay, it's also given here.

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So here's there's maybe an abstract talks, a bit about the case history. We talked about the setup and so here's.

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Document now you can read what our case history is and I'm asking you as soon as possible, but maybe your homework for tonight will be to read this case history and see what pieces of information you could think about. Adding tiny.

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Cases sooner patty a matter of our attention. We are we get a tattoo.

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Is especially in the the setup where we talk about, you know the geologic conditions I, you should, you might know much more about what wells have been drilled there and what types of information is available and what the real goal is. So.

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I'm, a stand-up Gujarati mom, oh maybe intelligent, Oracle turnouts- are only.

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Bass shortly leave.

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Immediately desert.

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Has a determinant in my body.

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Divided opinion of a lucrative, a information on generosity on eBay Oh Briana ago, set up through the rock Oh, even our sake, showers early start with a kite.

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Okay, so that's one homework for you. Let's come out back to our soundings.

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Kisame engine love, Emiquon are very high anxiety, so.

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We've talked about open source, we've talked about our resource, G, aside XYZ, so that gives you access to a number of things, but in particularly the course material that we have here. So that's your resource. You want to find out something about the slides. You want to find out something about the questions you go to. That course. Material.

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Without cost material Oh, mr. Edano pencil stem upon a ball and.

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The next thing is Jupiter notebooks, not.

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What either of your, if yo get it no sir, so.

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How do we connect computing software, okay, with data and with your research, or with your attempts to extract information from the data? So maybe some.

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Wedding, the other day, you know the lament the young male application. If.

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So we put it into something called a notebook and a notebook is going to look like this.

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So don't let it go alone. There are no protected by metal as a house of Allah Muhammad Allah is I. Think about it. So.

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You can see it's got the word Jupiter up here, I'm.

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A to be done ma, that's how a and.

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There is a big project in the United States and worldwide. That's devoted to this Jupiter project to.

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Be done projects rather American a thing. I talk about the one about the cable, TV, young media project path and one.

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Of the people, that's with the GWT team, Vincey Hagee is a prime person in this Jupiter project so to the.

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Front I'm on Lindsay Peggy's people know what.

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Time you to be dumb, I thought the Gabel yeah.

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We are very fortunate that she is on board and we are also extremely fortunate that a soggy kang who is at Berkeley is part of this team, because he has been one of the principal developers for the software that is running everything that you're going to see. So he.

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Gains and will jump the abyss you receptive viola.

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Hey tell Adama that's already software.

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Who can give, you know, develop lieutenant or not so.

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A notebook, it's like an it's, it's an interface. It's a way for you to interact it's a way for you to interact with this equation.

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So it's a way for you to interact with this equation at this geophysical survey, in a manner that you can understand, so that you don't need to know a lot of stuff here say.

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Dean, opel commodore the in command you of missing that, but that is a very underground how you go the equation, which I don't think below: I'm gonna take them whenever they learn I, know and.

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Why this is so effective- and you will see this by by the end of this morning- is that this allows you to take complex problems and ask questions and get an answer to questions by simply moving slider bars and changing parameters. Diamond.

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That bias of naughty month, if you have other made of ice, would be the how to accomplish and what cannot been able bodies.

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Doing what is your.

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Dentistry in activity.

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Kilometers, anyway, about a minute.

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So that is that's our goal. With these these interactive apps, you can explore by asking questions and then seeing the answer to those questions and then, when you look to see what is happening with the currents or the charges, then you start to understand what is the experiment so.

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The answer- interactive, interactive, Tarot name, vio application to determine whether they pollinate oh yeah, The Blob, take care of that routine. Initially, mobility, yeah medicals, our music, then that we are interacting to their application. The coupon so.

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Let's, let's start to think about this whole process and we're going to look at one slide and then I'm going to show you the we have and- and that is in this follows: if we take a battery and we hooked it up to the earth, okay, then we're it's like having a point current here that is going to distribute out everywhere. So the currents are are going to look like this. The battery has an electric charge, that's associated with it, and there's going to be an electric potential that is given by this.

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So basically falls off as 1 o'clock mark and the point current is also going to give a voltage that falls off as 1 upon R and depends upon the resistivity.

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Maybe that's probably self-explanatory other well, maybe maybe just the pictures and the wizard.

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At 30, but we don't, you know of dynamism, I mean you know T. Oh yes,.

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It's the television and this.

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Is some blue icons on your aa be right? How right am I sorry.

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So here is the the app for the dc2 layer for the foundation problem. This is.

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The app this is this is the app yeah I'm, not too happy about it, DC, Julia Foundation and what so.

C

You can see here, there's Jupiter appears through this.

A

Ago, Jupiter notebook to be done up: Oh, Gemma, Gemma, haha okay,.

C

And this is the this: is the earth no.

A

General mini t-bone and.

C

There's a stadium here in recent stivity I'm a.

A

Skill to bomb a resistant- yes, skill, development and.

C

We have this earth, it's got a layer over a uniform region. We call this the Hat space. So it's a layer, yeah I thought it's a layer over a half space layer.

A

Over half spaces with young men I have.

C

Space yeah like if we had everything in the universe that would be like the whole space. If we have just only half of that.

C

Well, we'll come back if you so here: here's our earth and now we're going to put do the experiment, there's a and a B. So a is the positive current and B is the negative M is the positive potential and and disconnected so.

A

I'm under oh, hey, FBI agent, came about in.

C

A

Are positive, Jessie down these.

D

Are all negative.

B

This is done and.

A

The N is a potential agenda.

C

For the app there's, some parameters that you I'm, not sure that you can see this.

B

C

A

Doctor yeah yeah, big SATs.

C

So a is the positive current B is the negative M is the positive potential and is the negative.

A

Potential I'ma drop impact. My statistical, the answer of positive was our electrons are a theater non-negative number Tara and that's our potential positive potential.

B

And that's our negative potential.

A

C

One is the resistivity of the first layer, rwanda.

A

For the Basel I, a resistivity with your around so.

C

This would be resistivity of the first layer and they.

A

One do that goes on, Who, I am and resistivity will go. One of.

C

Your man, yeah grown to is the resistivity of the second layer, reduce.

A

Or not to the annoy a resistivity command and.

C

The thickness the thickness of the first layer is H. There.

A

C

A

I think, nettabi time we had another yes circuit.

A

B

I have thickness.

A

C

So, let's just do something: let's take, but let's take it an earth and we're just going to put down a single electrode, a single current okay, the.

A

C

A

C

So here's here's a plot appear from minus 40 to 40 the.

A

Matter of podium or visiting nobody's the enemies that team.

C

A

C

I could put let's put the current down here at minus 30.

A

Minus 30 Lambeth up, yes, he's not chasing man; okay,.

C

So I came in I can put a current in here. So what do you think is going to happen for the currents so I.

A

A

C

If I put it, if I put it a current in here, how did the currents motor they kind of just go this way or down under.

A

The the chassis did the antenna.

B

A

C

To go comic-con.

A

They will go like it will tilt tilt.

C

Which, which way.

A

The only one yeah.

C

Just one current so that.

A

You will go in anyway.

B

A

C

I know it can.

D

Be positive all.

C

Right so, let's so now we can see right so up here, there's different buttons to to click so right now, we've got this. One click the model, my.

A

Job come on, we gotta hide, beat Holly, may I'm all done with their own a nightmare and the.

C

Model was rolled, one was 500 row, 2 was 500, so it's just constant okay, so it looks looks like this. So it's just very constant. So now we're going to put a current in here and then we're going to watch where your currents.

A

Flow, so the a mob current protects you to come up a little currents of the bomb, as it sits out.

C

So we have this parameter here: J Kevin.

B

C

Talked about that yesterday, that's the current density, James I know the.

A

C

Oh yeah, that's.

A

C

So if I have a plate, then it's the current per unit area that scrolling through them powerin thought unit 8. So if I click on that, then we're actually going to see the currents where the currents are G.

A

We're gonna make McDaniel Quran chapter XIV nestled together.

C

So, let's just let you, let's move this.

C

Let's put them.

C

So you can see what happens here. We have a current part here and then you know the lines of current, which I think is what you said are just distributed out everywhere.

C

Okay, so that's what the currents would look like and what about the electric potential, because I'm really interested if I'm on the surface, what the electric potential is, because that's what I'm going to measure with my voltmeter so.

A

These are you telling their car? Oh now, it's a very tight man, but they didn't able to honor my thumb and so I probably owe you any money. Didn't Java absolute I am less robust, a bizarre. It's a so. If I look at the potential to potential TT man, the.

C

Electric potential in the earth looks like this, and the value of the electric potential at the surface is something that just decays away.

A

C

A

Was I would be blocking your kingdom away while I did well and.

C

What we're now going to do is to see if, okay, if we just have a particular point, see do I have them.

C

D

Now it doesn't know.

B

D

Over 4 PI know.

C

C

Got me up depth.

D

C

D is equal to Rho I over 2 pi all right. Thank you. So.

C

Just one D: so if I have a current here, put it in that, then there's going to be a voltage which is Rho I'm over 2 PI R. So that means that the voltage is going to decrease as I go away from here. Right.

A

So that is what what takes got your honor voltage it on your noggin time.

A

C

What that's, what this curve is showing here, that the voltage is dropping as just at 1, over distance as you're going to win, but.

A

The way loves Diwali on your body, but.

C

We could take this and we can rearrange that to pounce.

A

You get off yeah yeah.

C

Is to by far the overall.

A

Nobody about that yeah! Oh, you can't see.

C

Okay, so we can take this, so this tells us what the potential is, but we could rearrange that to be. Rho is equal to two PI R.

B

C

If we do that, then the interesting thing happens is that if we measured this potential here and we computed the recent stivity from this formula- we'd actually get 500 ohm meters.

A

So it was a 500-yard right.

C

So that's, that's actually really pretty amazing. We put a current in the ground and we measure the potential someplace and then we use the formula and we get out the true reason. Students.

A

The potential was shot it with a show. Yah he's done it all. Oh, this is stick that thing out and.

C

It doesn't matter where I measure the.

A

Banana the dinosaur outlawed, they got me some love so.

C

Here's my my M measurement and minus 10 if I moved it to some other location, Emma.

A

Emma stand of latardo I ain't receptive to that one. So.

B

Finally, should I miss enough to presenter.

A

Blah blah over here.

C

I get a different potential pleasure down body when I put it into the formula. I get the true resistivity.

B

C

A

You're young or to calculate look like crap, so.

C

That is done with a with a single single current stores. Most often we will have a positive and a negative source. So let me do that da.

A

Da da no one of the first step to prevent a table is a table, the middle on the other door or wall mount. That goes don't take me Diana. The other night is young.

C

Up here you see that there's a number of buttons there's a pole pole, which is what I just did on that means that the only thing that's activated is the current electrode a and a potential electrode cam.

A

Current electrode coming that's from a growth potential and then an iPhone.

A

C

Could also have a pole, dipole.

A

Hold I'm going to be on it or I, takes me Monday yeah. So if.

C

I have a boy, a dipole.

A

C

Have a single pole for the current, but I have two points for the potential and AM and an amp, and those are these here. The dipole.

A

Of German say no current, let electric current narrative a bomb, a new particle medical charity, potential.

A

C

I could have a dipole pole, which gives me two currents eight and feet like do that.

A

Dipole ball and a Miss a no, so.

C

Now I've got two currents: a and B. So a that mean occurring, nickel, para obtener, and what potential.

A

With that shackle on most.

C

Cases that will deal with our more like dipole dipole now.

A

Thought to the typos typos, and oh my that was, that was a rough. No, yes, he dumb know who quotation heckles, where.

C

We've got a current at a positive current, a negative current B and every.

A

To answer in the new potentials right.

C

So those are these buttons up up here.

A

All right well machine in there cookies, on which they're down at your body, okay,.

C

So now, let's look at just a little bit at this at this dipole dipole dipole.

A

Dipole that it's now and.

C

If we have, we wanted to compute the currents.

A

Our food that isn't as I know.

C

So the positive electrode current as currents going out everywhere, the be electrode here which is negative, is just the reverse. So it's currents coming okay and if we put both of these together in the currents flow from the positive to the negative. So instead of just flowing straight down, there now flow in this part.

A

I'm, a real, positive or negative about mr. know this.

D

These hours are titanium, the bottom ended up a.

A

Mop head with water and political science, we have a limit and.

C

Notice that the resistivity is still 500 meters, so resistivity.

A

Ro d diamond and.

C

I am attending at the beginning of the document.

C

We break down a little bit more if you've got a.

C

Two currents and a potential, and then this is the voltage that you see where these letters here in a.m. means the distance between the a electrode and the electrode.

A

So I am Tara, ena and nanjiang. ah She got caught with your body, so do myself a good I, the M shadow of the ankle, Charlotte Airport, a good shot at all, that's wrong to electric current or non-current nakute omentum, a potential ambush ah ah and the kudos are and.

C

If we had an A and B two current electrodes and the end potential, this would be the voltage that we'd.

A

Measure there so they said well, they should have en boun enough with being informed about it, but.

C

We always measure a potential difference so in the instrument that Kevin bill last year that you'll see this year to take a measurement. We're going to put a bold meter connected to two probes to make a potential difference.

A

The cabinet don't need a.

D

Centimeter right, they.

A

Wouldn't show their talents it would wash on difference.

C

Yes, so what we're measuring is this potential difference, which is what REM show or temperature yesterday, which is just equal to basically the potentials from each of these individual dipoles, and this just becomes some geometric factor which we.

A

Call Gene's to Abdallah geometry, yet we are only for not only the column if I'm a challenger could be, and in China we shall and.

C

Now that we've got that, then we can represent and on.

A

Television alter resistivity or resistivity to measure this, you know the.

C

Current we know G, we can calculate the recent stupid.

B

Aren't babies on.

A

A resistivity time.

C

So that is that's what we see here with a and B and notice. So a man an R here and we get the resistivity of five hundred if I move these electric these potential electrode someplace. So, let's suppose, I I move without.

A

Electrical- and we will just reaching be over here.

B

C

So if I put a man and here I get different voltages, they get different numbers, so Delta V changes, but then the electro disc distances have changed and I still get the same. Resistivity.

A

So I'll put that shut up, take down our azimuth at position: number 9 at the air resistivity at the diamond phenomena. Okay,.

C

So that's that's. Some basic principles for just different rays for a half space now becomes interesting to say. Well what happens if I change the resistivity of the ground, so here.

C

Here our model was just a uniform earth. Alexi.

A

More anytime I want the end you can do that goes then. Yeah.

C

So, let's change it, so this is 500 ohm meters. Let's change it! How do we? How do we want Jake want change the layer in the background you choose.

A

Blue byung-eon Italy layers and background yeah.

C

A

Need we're gonna change something, so we got down lady middle.

C

So we got a row one row, two, let's change something.

A

The row one row: two values: are you tired? You know downs, yeah,.

C

Somebody change something.

A

C

Change the kick change the thickness okay. So how big.

A

Without time, man yeah Oh, 300.

C

But that's yeah: where did that sort of off our diagram? Here we go yanti god, let's kind of stick with the dimensions of this pocket right now. It's five now so I make camp okay, so Stan that doesn't make any difference, because we, the layer, still has the same resistivity as we had before so.

A

Maybe we change our resisted, you know how that thing broke down and I think, as we have suppose.

C

The upper layer was wet, okay,.

C

A

An animator over seconds, yeah.

C

So what resistivity might be want, if this so.

A

It's alright and I'm. Also monsoon is a resistivity chamber meeting enough about you say my identity.

C

And I even know about about yeah 120 sure, whatever okay, so 20, so the first layer is going to be 20 okay, now before okay. So, let's just let's just first of all think about how to use this.

A

C

We we saw for a uniform earth how the currents go.

A

C

Now we're gonna change something. So what what are we looking for? What I mean? What's.

A

A

C

From the point of view of the DC resistivity experiment, things that we could look at, you know ID, like the electric potential feel, or maybe the currents like, would that be pinterest just to see where the currents flow.

A

You know dope, you are covering that loosely guess, you're out of that same way as articles on your neck, that I.

C

Think the currents are very insightful. So, first of all, let's just look at a homogeneous, app space.

C

So here's here's an 8 electrode at minus 22 and a be at 23 and let's just look at the currents, see.

C

Right so there so every so! This is now now a uniform earth right. Okay, so now we say: okay! Well, what happens if I make an upper layer that is low, resistivity.

A

B

C

B

A

C

What do you think is going to happen to these currents? The yes, these out.

A

In the first layer, more okay.

C

B

C

Is good right, so here your you, you make a change, but before you hit the button you think like okay, what's what's gonna happen, oh I think it's it's more conductive, so I think maybe they're going to be up in the top. Okay.

A

Let's change so now.

C

We change this to 20.

C

Right so now you're right, so it's very conductive here most of the currents just go right. They just get channeled right through there, a.

A

Month, let's see double monadic Auckland, ah so I see double.

C

So that means that you're not really seeing very much down here you're, mostly seeing up here. Oh.

A

No man say not general battery Amazon, a bolo Iowa down with your theme. I've got negative thing with the other ones. Another.

C

Interesting things here is that the it's forged, the resistivity that we got before if we now put it in, is 38.

A

Without resistivity net boo-yan aconitine it off that's anything yeah. So.

C

It's not equal to 20, which is the top layer. It's not an equal to 500, which is the bottom. It's someplace in between. So.

A

I thought: oh boy, I'm, gonna, stay cool, I've got an.

D

Iowa Mike yeah.

A

C

So this is good right, you're, starting to kind of get some sense now what happens in the other case.

C

So what what's going to happen if we make it resistant.

C

They talk the top layer, oppose.

A

Allows our is this resistivity yellow me.

A

Aaron will go down deeper.

B

C

So somebody said: is gonna go down deeper, so how how why should we make the upper turret resistivity.

B

C

C

A

I suppose oh wow, god I'm gonna miss this. Did you try not to.

C

C

So now see what happens if we make it resistive a lot more. Is this.

A

New team yell delivered uh named as he's Omni on.

C

A

C

Doesn't want to.

A

Go through hi, my name is wise enough. Waffle doctor the.

C

Strength of the current is coded by this color bar the.

A

De calabaza, the jockey carrenza so.

C

We see this indeed Ziggy's out now. This is dark blue, so it's very low currents dodging.

A

Odds are no comment. They misleading on Kenya, whereas.

C

This is later it's it's up in here, so it's got more current, even though it's deeper.

A

Young nuclei that are current will dry out, but whenever physio Magua will proceed on.

C

And now, if we look at the apparent resistivity.

A

C

2,600 so that the top part ok was 5,000, and then we went to 500. So this again is part way in between it's, not as big as the talk resistivity, but it's bigger than the ball see.

A

Light down the doors are all opposed. All about I. Do you go parents? Resistivity is ro, of course, Oman. She did I, don't think the night I help them achieve I'm. So much in a biology lab a job. It's yachting.

C

So that that gives you some of the things that's an introduction to this app that I.

A

Thought the application of the nipples. Now, how do you make that happen and.

C

I think you can start to see perhaps the the power of this, because you can begin to ask questions about how the experiment is sensitive to the ear you can. They can ask questions about how the experiment is actually sensitive to the earth.

A

He dropped a tank arching up on a Yamaha.

A

C

What one more thing before before we go, let's just take a look at this case where we had with let's say 50 meters over over 500, and let us look at the apparent freezes, stivity imperative.

A

Services to tianmen and then down down IV so.

C

A

Just as goodbye Courtney.

C

Oh James yeah 88, so so we've got a layer. Ten meters thick, it's semi.

A

Died today come on up yeah, so it's it's.

C

Apparent resistivity is 88, so we're still feeling the effects of this layer below I've.

A

Got effectively and it'll be 98 upon painting, but.

C

What do you think will happen to the apparent resistivity if we just made all of this shorter.

A

Why we will do like this.

A

C

Do you think, do you think if we change the length of this array that we're going to change the apparent resistivity, the eraser down on me tonight.

A

B

A

It will change, it will change him.

B

C

Who says who says down? Who says up? Okay, I'm going to change a and B.

C

So right now a and B are minus 22 and 23 I gotta make.

C

Okay and now I'm going to love to see what happens under that circumstance. If the a and B look, let's get em out.

B

C

So in this situation here when a and B are partners, they're close together, then most of the current is flowing in here and the apparent resistivity has now decreased to fifty fifty seven. So it's even that's less than eighty eight, so you're right, it's getting it's getting smaller and the more we condense this whole array, the closer that we're going to get to just being sensitive to this shallow region.

A

So, my god, my parent resistant job of you, know EA, see job I raised.

D

A

Tomorrow they may give it hang out about next time, yeah. So.

C

Most people are used to going to call Schlumberger arrays, so much generates it right. So we're going to make a small number J array where we've got a man in electrode at minus one and one, and then we're going to look at current electrodes that are bigger or smaller slimejects.

A

C

Stronger shape, I mean.

A

C

In a Schlumberger array- and we spoke about that yesterday-.

C

So the a electrode is here and the B electrode is here and AM, and an are sitting close like this.

A

D

A

C

And this is how you're collecting your data here most.

A

Most commonly the imagine of Tony on a bank that aquatic so.

C

In in this particular case, here, we've got a and B at 10 meters away, and we can see that the apparent resistivity.

C

So the apparent resistivity is almost only the value of the discrete region in here. So very small. The currents are in this near surface region and that's basically what you see b.

A

Ma while we are there sending that abyss, you do this from. If.

C

We make the Schlumberger array bigger to make a and B glove like this, so we can put it at.

C

Let's put it up minus 20 and then we.

A

A

Wait a minute I miss me.

C

So now, if we make a and B larger, there's more current, that's going into the ground and the apparent resistivity is 8787 intent on it. So we can see as the larger that we make this the higher the resistivity is.

A

C

So if we plot apparent resistivity against AV and usually we have it /, that's what you're traditionally.

A

Done if I mean I will not honor baron resistive volumes in his name, so here.

C

Are yeah so here our earth was was 50 over 500? Was it wasn't.

B

C

50 over 500, when we're very sure, a and B are short, then we're just seeing this. This talk meeting has to be get an apparent reason, stivity of something that's close to 50, so.

A

C

First, we had a nice and gentle, yet I, don't know how.

A

That I can set up these. How about B but Baron resistant to be nos a one, significant and.

C

Then, as we go larger so here a B upon two was.

C

20, so a be a point, so this is this is like five and here it's 20 and by this time it's maybe seven looks like yes and if we made a be even much larger sure.

A

In any book, while we approach Auntie Mame, since you know Aaron resistivity at that bar so.

C

A

C

That that's as far as I I can go here. I get the apparent resistivity of a hundred and thirty-five yeah.

A

Those are not that far. That's.

C

So you can see that where you start to, we start to make a curve apparent resistivity as a function of array spacing or the length of the array and we've I didn't.

A

Quite a poem with debutante Mara resistivity chamber.

C

Initially, we just are sensitive to the reef near surface, but gradually, as the array gets bigger, we're sensitive to what's happening at depths or neck.

A

Will tell you probably to another or resistivity Nair: has a probe I made no sense lumen, so another cheerleader guys are counting in an economy. Rio.

C

So what I'd like to do now is to have you answer some questions. So, first of all, I tell you at the top of the app suppose.

A

Ohm Abdi oppose Allah questions. Cheap eggs put up with their connection.

C

B

C

Well, I showed you earlier.

C

Actually we're still okay, so, let's, let's now switch gears and and try to get people to download this particular app.

A

C

So this is a good time for a break. How many people have now Devin's been going around.

A

But now Cindy buddy there.

D

So I was able to get anaconda installed for most people, but we.

C

Can't at the apps internet, because that requires.

D

Communication: okay,.

C

So I have a I've got a phone. You could use his hot spot. I.

D

Think I don't think.

D

C

See what we can, but we could, if we, if we can, please just give answer anybody who has to be anybody who has got the apps in.

A

C

Hoodie the note that you.

A

Can open it? Oh yeah man, one.

D

C

Nine people and these you actually have been able to access one of the notebooks.

D

The volunteer, the Anaconda prongs, okay,.

C

So the next step is to find the anaconda prompt and get them function, get the F function. So for that we need internet.

C

How many people can you ask for their computers to get Internet.

A

C

A

C

Then we just need to get instructions. Do you want to take we'll have a short break, so let's have a short break down in Baja.

B