►
From YouTube: DISC Delft Morning
Description
Dr. Doug Oldenburg presents Geophysical Electromagnetics: Fundamentals and Applications in Delft. 1/2
A
C
A
B
B
Yeah
so
we're
having.
This
is
the
s
e-g
disc
course
of
lecture
magnetics
fundamentals
and
applications
and
yeah
we're
traveling
around
the
world
and
trying
to
talk
to
people
about
electromagnetic
geophysics
and
kind
of
show
them
what
the
potential
is
and
demystify
it
and
yeah
get
people
to
be
really
involved
in
it.
But
before
we
actually
start
that
I
wouldn't
mind
finding
out
who's
actually
in
the
audience
and
sort
of
what
you're
doing
and
why
you're.
Here.
C
D
A
F
Yogge
won't
use
the
word
Michelle
research
accidentally,
maybe
related
to
science
week,
and
they
told
me
so
the
contrasting
methods
and
severity
magnetic
spectrum
kinetics
electrical
methods,
as
I
mainly
concentrated
them
on
CSN
after
I
returned
enough.
I
started
giving
courses
like
50
courses
on
seismic
data
acquisition
and
processing,
also,
basically,
physical,
deposition,
processing,
more
suspect
methods
and
in
reservoir.
Monitors
I
used
to
be
very
busy
at
that.
But
since
the
world
I.
D
Jana,
lots
of
engineering
section
extremists
a
pompous
eccentric,
so
we
are
developing
a
new
technique
for
reducing
self-pity,
only
not
a
partner
to
project.
We
would
like
to
move
into
our
implementation.
So
in
the
previous
case,
we
use
ERT
to
see
whether
we
reduce
a
community,
whether
we
intercept
it.
It
was
really
nice.
B
Good
I,
thank
you
for
that,
so
that
that
actually
is
pretty
valuable
information
for
me,
because
we've
got
a
lot
of
there's
a
lot
of
stuff.
I
could
talk
about,
and
it's
helpful
to
kind
of
know
what
the
background
people
is
here.
Basically,
all
academics
I
mean
mostly
PhDs
and
postdocs
a
lot
of
background
in
seismic,
not
so
much
perhaps
in
in
am
and
yeah.
Maybe
we
could
fill
some
of
those
gaps
up,
yeah
advance
where
everything
is
going.
B
Without
these
three
people,
it's
it
really
is
the
people
in
the
local
art.
You
know
at
the
local
level,
where
we
go
to
that,
make
all
the
difference
in
the
world,
so
I
think
I
thought
maybe
before
we
really
start
I'll
give
you
just
a
bit
of
background
about
myself
and
also
just
make
a
couple
of
comments
with
respect
to
energy.
So
I
was
inspired
by
a
couple
of
really
great
people:
Bob
Parker.
B
You
know
that
name,
Freeman
Gilbert,
George
Bacchus
in
the
late
nineteen
teens
late
1960s
and
these
people
are
all
kind
of
pioneers
in
the
geophysical.
Inverse
problem
and
I
happen
to
be
at
Scripps
is
do
the
oceanography
I
just
want
to
happen.
This
is
a
timeline
here
and
I
thought
it's
it's
kind
of
useful,
just
to
sort
of
see
where
inversion
has
progressed
and
kinds
of
problems
that
we
could.
B
But
we
we
can
solve
the
full
problem
in
some
cases
like
gravity
magnetics,
maybe
with
a
hundred
thousand
the
trade-off
is
they
have
very
good
resolution,
but
at
least
you're
solving
the
exact
problem
by
the
time
in
2005
to
theirs.
We
could
start
to
solve
the
3d
frequency
domain,
IAM
and
tied
them
in
him
with
sources.
B
G
B
There's
there's
number
of
things
that
have
really
advanced
the
whole
field.
One
is
basically
instrumentation
and
data
I
mean
we
can
now
acquire
both
high
quality
and
large
amounts
of
data
that
we
just
had
not
been
able
to
see
before,
and
that
allows
us
to
do
very
large
scale
problems.
Here's
something
where
we
have
groundwater
problem
in
in
California,
in
various
confidence,
both
in
North
America
and
in
Australia,
there's,
actually
continental
wide
programs
to
recover.
B
B
These
are
moving,
so
why
should
these
are
different,
different
grits
and
yeah,
so
that
is
an
offshore.
Perhaps
that
resonates
with
few
people-
marine
C
SEM,
trying
to
use
that
for
diversity.
I've
got
a
case
history
that
will
talk
about
some
of
these
problems.
The
other
thing
is
that
we're
in
a
situation
where
things
have
changed,
remarkably
with
respect
to
web
resources
and
open
source
sources,
and
that
allows
us
to
kind
of
collaborate
with
people
to
share
to
make
some
tests
and
just
kind
of
changes
the
way
people
work
I
will
be
talking
more
today.
B
But
these
things
all
kind
of
allow
a
different
kind
of
way
of
interacting
with
people
and
and
the
other
thing
is,
we've
got
many
applications
that
are
now
arising
so
anyway,
electromagnetic,
for
instance,
could
be
used
for
mineral
exploration,
contaminants,
groundwater
get
thermal
energies.
We
thought
of
that
unexploded
ordnances,
hydrocarbon
slope,
stability.
You
keep
technical,
so
there's
there's
a
huge
number
of
problems
up
there
that
are
important,
and
perhaps
it's
possible
for
electromagnetics
to
play
some
role
in
these
maybe
not
be
a
complete
solution,
but
at
least
play
some
of
the
work.
B
So
that
seems
that
we've
gotten
basic
ingredients.
We've
got
first
of
all
problems
to
be
solved
as
important.
We've
got
high
quality
data.
We've
got
the
ability
to
invert
these
different
e/m
datasets
and
we've
got
web
tools
to
communicate.
So
okay
seem
like
we
should
be
good
to
go.
But
the
question
is:
okay:
what's
the
roadblocks,
why
isn't
this
really
taking
off
and
there's
actually
a
lot
of
roadblocks
and
just
a
couple
of
conference,
you're,
already
kind
of
identified
and.
B
That
you
know
in
in
general,
gia
scientists
just
don't
really
realize
the
role
that
e/m
can
play.
I
mean
it's
just
haven't
really
kind
of
connected
with
it.
The
the
terminology
is
sometimes
confusing.
Don't
really
understand
the
technique,
don't
understand
the
technology,
and
you
know
people
in
eeehm
talk
about
all
the
real
part
of
the
date
or
the
imaginary
data.
You
know
like
okay,
what
is
what
is
all
that
stuff
and
everything
is
it's
it's
not
intuitive.
B
If
the
seismic
is,
is
wonderful
in
this
sense,
because
you
know
you
can
see
a
wave
go
down
and
reflects
off.
It
comes
back.
It's
like
okay,
I
got
it.
Electromagnetic
is
not
that
way.
It's
a
diffusive
process,
and
you
know
the
data.
You
cannot
look
at
the
data
can't
understand.
What's
going
on,
so
that's
that
makes
it
the
other
day
is.
Robot
is
really
coming
to
grips
with.
B
Even
if
you
kind
of
get
you
through
all
these,
then
you
have
to
say:
ok,
Juan
donators
choose
it.
Certainly
so
in
inside
Frank
I
mean
again
there's
different
kind
of
surveys.
You
can
use,
but
they're
all
basically
setting
up
a
Gotham,
so
there's
some
kind
of
explosive
and
hitting
acoustic
elastic
energy
level.
Food
in
electromagnetics,
as
we'll
see
today,
there's
just
a
whole
host
of
surveys
and
they
can
be
quite
different.
B
Should
you
use
a
DC
survey?
Should
you
use
a
survey
that
is
working
in
the
frequency
domain
or
time
domain?
And
where
are
my
surveys?
Are
they
in
the
air
in
the
ground,
on
the
ground,
surface
of
borehole,
and
always
the
big
question?
What
expect
for
resolution
but
resolutions
always
the
big
thing,
what
what
scale
can
I
see
and
finally,
the
other
thing
that
isn't
existing
in
one
places,
and
this
is
sort
of
a
comfort
level.
You've
got
a
problem.
You
want
to
somehow
solve
this
problem
and
see,
if
maybe,
if
a.m.
is
useful.
B
So
these
things
here
are
really
all
kind
of
roadblocks
because
they
don't
exist
really
at
this
time
for
most
people,
so
the
goal
of
this
course
is
actually
to
kind
of
get
rid
of
those
guys
so
we're
gonna
spend
today
and
by
the
end
of
the
day,
I
think
if
you
I
think
you'll
feel
like
there's
a
big
cross
through
most
of
this
stuff.
So
that's
that's
the
goal
we
can
accomplish
that
I
think
so
it
seems
that
we're
in
a
position
where
we've
kind
of
got
a
perfect
storm,
because
we've
got
all
the
pieces.
B
B
F
F
B
B
So
the
the
goals
for
the
disc
I
think
inspire.
You
I
just
see
the
variety
of
problems
in
which
your
physics
or
e/m
has
made
a
difference,
and
we
want
to
illustrate
that
effectiveness
through
case
histories,
so
a
large
amount
we
took
actually
look
at
places,
will
present
fundamentals
but
then
see
ok.
How
did
that
actually
get
applied?
And
when
you
see
the
successful
application,
you'd
like
oh
well,
maybe
I
could
use
that.
We
want
to
build
a
foundation.
B
Eeehm
GSI
that
it's
kind
of
a
portal
to
a
lot
of
information
on
you
know
both
on
them
fundamental
side
as
well
as
on
one
set
realistic
expectations.
This
is
extremely
important.
Very
often,
geophysical
techniques,
eeehm
have
been
oversold,
I
mean
in
principle.
They
seem
like
they
should
work
really
well,
but
in
practice
you
know
the
resolution
is
not
what
you
need
or
whatever.
B
So
you
need
to
have
an
idea
for
a
particular
kind
of
survey
and
what
you
might
and
another
objective-
and
this
is
actually
really
important-
one-
is
to
kind
of
develop
more
of
a
community
here
where
people
can
talk
and
interact
and
to
share
problems,
to
share
data,
to
share
questions,
and
just
continue
on
towards
that,
like
an
open
source
environment
where
you're
acting
more
as
a
collective
community
and
the
last
thing
is
kind
of
related.
That
is
that
we
want
to
sort
of
capture
case
histories
that
are,
you
know.
B
B
H
B
It's
a
wonderful
book,
it's
got
all
kinds
of
information
in
it
and
it's
a
classic
for
graduate
students
to
look
at
all
my
graduate
student
support.
But
you
know
it's
not
a
particularly
insightful
thing
in
in
many
respects,
because
you
can't
interact
with
a
lot
of
this
stuff.
That's
in
there.
So
that's
been
a
motivation
for
us
to
develop.
Chits,
yogya
suicide
and
part
of
that
problem
is,
is
kind
of
connecting
the
theory
up
with
the
application.
B
So
we've
got
a
number
of
case
histories
that
we're
presenting
and
we've
developed
a
kind
of
a
format
for
how
a
case
history
might
be
presented
and
I
think
most
businesses
would
kind
of
work
through
the
thing
and
in
the
same,
an
order
where
you
first
of
all,
ask
okay.
What's
the
question
that
I
want
to
address
here
and
what
might
physically
looks
like
this
property?
What
survey
should
I
use?
What
am
I
data?
Looking
like
what
processing?
B
To
see
how
well
that's
so,
we
find
by
Anna
parsing
all
our
work
out
int
into
these
sort
of
seven
steps
that
it
really
helps
in
that
communication
of
trying
to
figure
out
okay,
where
exactly
am
I
in
this
process.
So
you
can
communicate
with
other
people,
and
it's
also
a
nice
way
of
kind
of
condensed
accounting
information.
B
B
G
B
H
G
B
B
B
B
B
B
B
Able
to
see
this
whole
thing
right
from
the
beginning
to
the
end
is
that
it
puts
everything
in
perspective
you
suddenly,
by
the
end
of
the
end
of
the
day
you
kind
of
like
okay
I
get
it
I
got
this
kind
of
a
problem.
I
could
use
you
know,
I
can
use
an
inductive
source
on
this,
and
I
could
get
X
amount
of
information
or
I
need
actually
to
have
a
grounded
sources.
B
B
B
Same
and
you
walk
in,
and
here's
one
that
was
I,
thought
tickety
program
shall
be
named,
Doris
Lessing
and
she
says
that's
what
learning
is
you
suddenly
understand
something
that
you've
understood
it
all
your
life,
but
in
a
new
way
and
I?
Think
there's
a
lot
to
be
said
for
that
like
so
sometimes
you
feel
like
okay,
well,
I
know
all
that,
but
maybe
if
I
can
present
something
just
a
little
bit
differently
and
it
becomes.
E
B
B
We
want
to
talk
to
you
capture,
information,
about
your
local
problems,
that
you're
actually
working
on
and
just
discuss
where
eeehm
could
play
a
role
and
will
also
use
tomorrow
to
talk
about
more
technical
things.
It
kind
of
depends
upon
the
audience
we
were
just
in
Australia
and
there
everybody
was
really
interested
in
eeehm
decoupling
because
they
were
working
on
all
kinds
of
IP
problems
and
they've
got
big
conductive
overburden
other
places.
B
B
E
B
B
B
Anyway,
it's
just
a
way
of
communicating.
You
can
make
a
group
within
slack
and
share
problems,
upload
pictures
and
you
can
just
ask
questions
and
it's
just
a
nice
way
of
informally
doing
a
sit
back.
If
you
had
your
computer
and
you
joined
a
slack
channel
here,
even
while
I'm
talking
you,
you
know,
you
could
write
something
down
sit
this
guy's,
crazy,
I'm,
not
sure
what
he's
talking
about,
but
I
don't
want
to
raise
it
with
my
hand,
right.
B
So
that's
the
way,
communicating
and
then,
as
far
as
contributing
we're
always
on
the
lookout
for
case
histories
and
content.
So
people
could
kick
can
contribute
to
the
are
open
sources
and
said
pay
which
we'll
talk
about
a
lot
more
tomorrow
forward.
Modeling
aversion
using
Python
how
many
people
use
Python.
B
B
H
B
B
B
There
is
like
six
or
seven
orders
of
magnitude
difference
which
is
huge
scale
so
from
seismology.
You
know
factors
of
twenty
percent-
forty
percent
here
how
many
orders
a
lot
of
things
that
we're
interested
are
kind
of
in
the
middle
here
plays
tools,
hybrid
car
consultants,
the
reciprocal
of
resistivity
is
contacted
me.
That's
it
either
Siemens
per
meter
or
millimeters,
and
it's.
D
B
Often
it's
fasted
as
magnetic
susceptibility.
Again,
that's
not
a
logarithmic
variation.
There
is
minerals
that
have
rocks
and
minerals
that
have
very
rolled
magnetic
susceptibility.
The
big
guy
on
the
block
is
all
its
magnetite.
That's
very
magnetizable.
In
other
words,
so
if
you
put
up
a
little
magnet
by
piece
of
magnetite
but
again,
you've
got
sort.
B
B
Systems
of
regarding
to
be
work
with
gotta
have
this
generic
slide,
in
which
we
know
geophysical
experiment
is
one
which
you
have
a
source
right
to
put
imaging
in.
It
interacts
with
various
physical
properties,
and
you
get
something
so
there's
three
different
physical
properties
and
they're
all
connected
through
Maxwell's
equations.
B
H
H
B
You
know
here's
Maxwell's
equations
in
its
entirety.
These
are
the
time
to
me.
Is
there
in
the
frequency
domain
and
he's
telling
us
how
a
time
varying
magnetic
field
generates
an
electric
field
or
how
the
curves
are
incident,
so
there's
n
equations,
then
we
also
have
to
have
constitutive
relationships.
B
I'm
not
going
to
relate
any
particular
field
like
an
lacking
field
to
the
plots.
So
here's
a
current
but
and
the
relationship
involves
at
this-
we
got
three
three
kind
of
transitions
of
relations
each
having
a
different
physical
property.
That
is
so.
Those
actually
allows
to
us
to
solve
every
electromagnetic
problem
that
we
have
so
long
as
we
apply
a
source
and
if
we
have
boundary
conditions,
then
this.
E
F
So
yes
would
be
hopeful
safe,
you
can
do
an
experiment
or
when
you
refer
back
to
the
equation
together
that
you
say:
okay,
we
see
in
the
app
now
this
has
an
e,
but
look
at
the
equation.
You
could
have
predicted
that
or
see
it
from
the
equation
itself,
so
that
makes
the
equations
may
be
more
understandable
if
you
need
feeling
what
I'm
doing
it
yeah,
it's
not
impossible.
Well,.
B
It
is
and
I
think
we
can
take
it
one
step
further,
and
that
is
that
by
showing
where
the
field
or
what
kind
of
fields
are
available,
what
where
the
currents
are
where
the
charges
are
I
think
you
get
a
real
physical
understanding
for
what
the
process
is.
So
that
combination
not
only
of
the
equations
but
then
also,
you
know
sort
of
application
modules
that
allow
you
to
kind
of
show
what
part
of
an
object
is
being
illuminated
by
a
particular
source.
That's
very
insightful.
B
So,
let's
parse
that
down
a
little
bit,
so
we
have
had
our
sort
of
general
diagram
right
here
and
first
thing:
we
have
to
worry
about
as
a
source.
So
what
I'm
going
to
use
for
source?
So
there's
two
kinds
of
sources:
one
is
inductive
source,
so
this
is
an
inductive
source.
It's
basically
a
loop
of
wire,
that's
going
to
be
carrying
a
current
and
that's
going
to
inject
energy
into
the
ground.
The
other
is
a
grounded
source.
Sometimes
it's
called
galvanic
source.
So
in
this
case
here
there's
two
current
electrodes
that
are
so.
B
Those
are
the
two
types
of
sources
so
inductive
and
driving
within
any
of
these
sources.
I
can
put
a
different
weight
form
I
can
put
in
a
harmonic
wave
form.
So
we
usually
use
talked
about
that
to
speak,
like
a
frequency
in
system
or
you
put
in
a
transient
where
I
have
time
occurred,
is
on
and
then
then
there's
also
question
about
location.
Where
is
the
source?
Well
and
we
do
will
show
you
a
number
of
airborne
surveys.
B
B
H
B
B
Period
or
hi
period,
that
would
be
an
appreciative
domain
or,
if
I'm
measuring
a
time
domain
system,
what
time
channels
do
I
want
to.
So
those
are.
Those
are
options,
and
you
know
each
survey.
You're
gonna
have
to
kind
of
make
a
decision
about.
Okay.
What
am
I,
what
am
I
got?
And
then,
when
you
have
these
fields
and
there's
even
a
question
about
you
know
which
components
should
I
have
do
I
want
to
measure
just
an
X
component
or
like
a
puller,
and
then,
where
are
those
receivers?
Are
they.
B
If
we
come
back
to
these
three
problems,
the
reason
that
I
kind
of
brought
them
up
would
step
in
each
of
these
three
problems.
Although
they're
kind
of
connected
with
a
number
of
physical
electrical
conductivity
is
the
one
that
goes
through
all
of
them
so
because
electrical
conductivity
is
so
pervasive
as
far
as
being
a
diagnostic
property,
where
accident
the
constitute.
B
F
B
So
the
basic
experiment
here
is
this:
so
we've
got
a
source
and
with
money
put
in
Turkey
and
I
I'm
going
to
try
to
stick
with
resistivity,
so
granny's
rope
and
the
relationship
food
segment
low.
Is
that
one
it's
just
the
reciprocal
of
Yemen,
but
I
will
confess
I'm,
probably
going
to
just
use
resistivity
and
conductivity
intermittently?
It's
just
you
just
get
used
to
it.
That's
might
be
sort
of
one
thing:
cm
people
do
so.
B
C
B
So
we
come
back
to
the
statement
we
showed
this
table
a
bit
ago.
Conductivity
varies
by
many
orders.
Thank
you.
The
thing
is
actually
very
important
here
is
that
the
conductivity
is
really
depends
on
a
lot
of
things
that
are
associated
with
a
pencil
draw
height,
but
also
depends
on
the
porosity
and
then
it's
how
these
pores
are
connected,
and
then
what
the
nature
of
the
fluid
is
in
the
pores
and,
if
there's
any
kind
of
a
solid
matrix.
B
B
Pseudo
sections
and
of
that
case
the
street
will
show
its
mineral
exploration
and
we
also
have
one
for
down
monitoring
using
self
potentials,
we'll
see
how
far
we
get
to.
That
will
certainly
do
at
least
one
case
history.
Yet
today,
so
here's
the
basic
experiment.
This
is
a
conceptualize
diagram
of
a
mineral
deposit
index.
There's
an
overburden
here
that
is
fairly
acidity.
B
The
deposit
itself
is
like
this.
There's
a
conductive
core,
this
blue
region
on
top,
is
a
resistor,
it's
all
that
possible.
So
that's
the
thing
that
you'd
really
like
to
find
iTunes
this
general
utilization.
You
can
set
up
this
resist
in
the
experiment,
which
involves
first
of
all,
a
source,
so
we
need
a
current
source,
we're
going
to
take
a
generator
two
probes
and
now
that's
of
currents
and
then
we're
going
to
measure
some
attentions
option.
B
One
of
the
fundamental
things
that
we'll
talk
about
in
depth
is
that
as
the
currents
go
through
the
object
here,
it's
going
to
require
that
there
be
electrical
charges
that
are
set
up,
so
those
electrical
charges
give
rise
through
Coulomb's
law
to
electric
voltages
that
you're
going
to
measure
up
up
in
the
circuit.
So
that's
basically
the
idea
but
turn
in
into
the
ground
about
flow
of
current.
So
your
objects,
you
can
end
up
setting
up
always
charges
and
then
you
record
the
potentials
at
the
surface
or
death.
B
So,
okay!
So
that's
the
basic
experiment.
How
do
we
actually
go
from
that
to?
How
do
we
get
the
resistivity
of
the
ground?
So
here's
our
Maxwell's
equations
again
and
for
the
artery?
But
when
we,
when
we're
doing
this
experiment
with
DC,
it's
called
DC,
it's
direct
current.
It's
it's
steady
state,
so
nothing
changes
in
time
and
because
nothing
changed
in
time.
There's!
No!
E
B
B
So
why
is
that
important?
So
imagine
that
we
can't
get
hurt
Pro
and
we
just
inject
the
current
into
the
gun,
and
now
you
can
imagine
how
the
Hertz,
according
to
well,
everything
is
homogeneous,
so
current
and
the
voltage
that
we
have
away
from
that
from
that
current
is
governed
by
this
equation
here,
where
R
is
just
the
distance
where
you
are
alright,
and
so
the
voltage
is
going
to.
B
B
That
if
we
were
at
any
place
of
your
away
from
that,
currently
we
just
measure
the
voltage
six
point:
nine
and
we
put
it
into
this
formula.
So
we
just
simply
rearrange
this
so
that
the
drugs
can
all
relate
to
them
all
the
features
metric
the
current
this,
so
we
know
anything
and
we
knew
that
and
we
actually
get
that
the
resistivity.
E
B
The
earth
is
500,
ohm
meters,
which
is
okay,
so
that's
the
connection
measure
a
single
voltage
and
we
could
actually
get
the
resistivity
of
deer
in
practice.
Of
course,
we
can't
do
that
because
to
put
current
in,
we
actually
need
two
electrodes,
so
we're
going
to
be
consistent
and
that
the
positive
electrode
it's
going
to
label
it.
A
and
B
is
going
to
be
the
negative.
B
B
C
C
G
B
So
what
happens
if
we
start
to
make
things
a
little
bit
more
complicated?
So
now,
if
we,
if
we
put
on
a
layer
that
has
a
low
resistivity
of
a
surface,
the
way
thing
is
going
to
happen
to
see
the
currents
in
here
I
just
they're
kind
of
getting
what
you
expected.
Here's
the
positive
here's,
the
negative!
If.
A
G
B
B
So
there's
a
couple
of
things
that
come
into
play
here:
one
is
called
sounding
and
the
other
that's
called
profiling.
We're
going
to.
First
of
all,
it's
sounding
the
idea
with
sounding
is
that
so
I'm
standing
here
and
I
kind
of
like
to
see
what's
happening
down
below,
especially
if
I
imagine
that
the
earth
is
just
layered
and
now
I
want
to
somehow
get
some
information,
but
what's
happening
your
surface
so.
D
B
G
G
B
Going
to
have
something
different
colors
for
JSON
nobody's
really
are
quite
a
mentally
different,
like
different
ways
in
which
people
collect
data,
it's
good
to
know
the
names
and
our
idea.
What
the
salary
curve
is
we're
actually
going
to
try
to
build
up
something.
It
looks
progressively
starts
up
shyamalan,
let's
put
this
so
here's
the
first
one,
so
we
never
started.
So,
let's
assume
that
we've
got
our
curt
electrodes
are
really
close
together.
You
can
see
what
happens
here,
so
this
is
still
the
same
figure
that
we
have
these
forward.
This
is.
B
B
G
B
Starting
to
get
an
increase
from
that
parents
divot
and
it
can
go
out
and
even
more
now,
we've
got
239.
So
here's
here's
what
that
silent
curtain
start
the
total.
So
it's
all
kind
of
intuitive.
You
can
see
that
these
current
electrodes
get
farther
way
that
you
just
beat
less
influenced
by
this.
It
is
interesting.
This
will
come
into
play
a
little
bit
later,
that
even
at
this
distance
here
between
the
positive
and
the
negative
electrode,
the
60
meters
and
the
layer
thickness
is
only
aimed
you
still
do
not
have
an
apparent
resistivity.
B
B
B
B
D
B
Inversion
to
start
off
with
our
survey
collect
the
data.
Here's
our
gate
now
we're
going
to
think
of
things
we're
going
to
invert
them
or
do
this
processing
to
actually
recover
something
that
has
true
depth
and
resistivity.
So
in
this
case
here
the
written
red
line
is
the
output
from
the
inversion,
and
this
is
the
true
depth
and
that's
a
realistic
turn.
So
it's
not
exactly
like
the
real
model,
but
if
we're
looking
for
something
it's
a
little
bit
smoother,
but
this
actually
fits
the
data.
There's
some
valuable
information.
So
that's
the
process.
E
B
B
There's
concepts
that
I
want
to
bring
up
here
and
that
is
like
what
happened.
I
talked
about
these
currents
that
are
kind
of
going
through
the
body
Kirk
here
those
two,
this
body
and
comes
back
and
what
actually
is
going
on
here.
Let's
just
take
a
little
bit,
first
of
all,
a
steady
state,
so
that
means
that
the
current
has
to
be
a
constant.
B
F
B
1
is
not
equal
to
Sigma
2,
so
we're
going
to
do
something.
Then
that
means
that
V
1
is
not
equal
to
so
that
means
I
am
going
to
have
a
change
in
the
electric
field
from
this
side
to
that
side.
So
that's
an
important
consequence.
So
you
imagine
I've
got
something
coming
through
and
now
the
electric
field
changes
dista
to
you.
So
what's
going
on
there
every
time
you.
B
H
B
Pointing
the
other
way,
so
it's
discontinuously
changing.
So
that's
what's
happening
here
so
as
I'm
putting
a
current
through
there,
there's
actually
going
to
be
a
charge
buildup
and
it's
those
charges
through
Coulomb's
law
that
actually
gives
rise
to
that
electric
field
that
I
measure
up
top
and
it's
my
potential
difference
charges.
They
play
a
huge
role
in
electromagnetics,
here's
one
basis
for
so.
Let's
just
take
a
look
at
that
a
little
bit
more.
B
So
let's
go
back
and
now,
let's
put
in
a
as
a
series,
so
we're
going
to
have
a
conductive
sphere
and
so
that
the
currents
going
to
come
in
through
here
and
then
there's
the
electricity
and
I
think
intuitively
just
because
of
what
we
don't
worry,
seven,
what's
gonna,
what
what's
going
to
happen
to
the
current
Rock?
What's
going
to
happen
to
the
currents
in
in
spirits,
so
imagine
you've
got
initially
just
a
homogeneous
background,
and
now
you
plunk
in
a
big
conductive
sphere.
What's
going
to
happen,
how
are
the
currents
can
change.
F
B
B
F
B
B
Its
really
that
change
in
those
potentials
that
are
going
to
be
that's
our
signal,
that's
the
thing!
That's
characteristic
of
that
spirit,
so
think
a
little
bit
more
of
a
of
a
poster.
Welcome
to
see.
Okay.
How
is
that
EC
resistivity
experiment
going
to
work
so
we've
got,
let's
suppose
a
500
millimeter
background.
We
got
a
very
conductive
sphere,
that's
here's!
A
here's,
our
charges
and
now
we're
going
to
put
down
my
probes
here,
measure
my
potentials
and
when
I
do
that,
I'm
going
to
get.
G
B
Depending
upon
where
I
go,
I
get
a
different
number.
So,
if
I
put
microbes
over
here
and
I
get
in
heret
Mississippi
at
500,
so
that's
kind
of
interesting,
isn't
it
I've
got
a
background
of
500
and
I've
got
a
conductive
skier
there
and
when
I
was
through
here,
this
is
seem
intuitive
to
me.
Like
okay,
I've
got
a
very
studious
less
than
my
background
good,
but
what's
happening
here.
How
is
it
that
we
could
actually
get
an
apparent
resistivity,
that's
larger
than
the
background.
H
E
B
It's
just
kind
of
think
a
little
bit
more
about
what
a
patoot,
what
your
potential
measurements
really
are
and
what
the
relationship
is
between.
You
know
the
plus
and
minus
signs
of
your
volt
meter
and
these
charges
that
are
are
here.
So
we
can
take
a
take
a
look
at
how
these
how
these
charges,
which
are
really
the
source
of
the
measurement,
are
directly
effectiveness
but
you're.
Not.
This
is
actually
also
perfect
if
you
and
I
kind
of
can
CDC
resistivity,
whether
you
like
to
think
in
terms
of
currents
or
jargon.
B
F
B
G
B
B
It's
basically
going
to
be
500,
0
meters,
all
the
love,
because
only
Oh
deal
at
the
FC
is
just
you
know
the
effects
of
what's
happening
very
near
surface,
and
that's
just
going
to
be
up.
If
I
can
do
it
the
system
and
make
it
bigger,
that's
something
it
looks
like
this.
Yes,
as
I
go
along
here,
then
I'm
going
to
get
a
profiling
curve
that
looks
like
this
over
time
of
the
body
I've
actually
raised
to
have
a
pair
of
resistive,
insignificant,
great
and
again
I'm
going
to
be
over.
C
B
B
B
That
that's
right
and
that
time
to
actually
get
that
going,
is
for
all
the
types
of
purposes
its
detainment
to
develop
that
piece.
Each
that
happened
very
early,
okay,
so
there's
some
basic
setups
here.
These
are
words
that
you
completely
swear.
Never
to
talk
about
great
I've,
also
taught,
but
often
in
gradient
grade
to
put
currents
out
here
and
then
you
just
measure
the
potential
difference
as
you're
going
here.
B
Assortment
then
you'll
have
things
like
a
dipole-dipole
or
ready.
So
here
you've
got
you
know
just
occurring
to
you
got
your
potential,
so
they
can
just
sort
of
move
along
at
something.
That's
it
the
things
that
you'll
often
especially
mineral
decoration,
it's
like
a
pool
bike,
and
in
that
case
one
of
the
current
electrodes
is
just
drag
way
up
to
happening
on.
D
C
B
Some
stuff
here,
that's
that's
about
me.
This
picture
does
not
tell
you
anything
particularly
about
what
the
geology
is,
is
really
like.
It's
a
way
of
plotting
the
data,
but
even
that's
that's
how
it
is,
and
that's
what
is
pseudo
section
so,
as
I
said,
that
kind
of
it
that
doesn't
tell
you
anything
information
about
the--
the
earth.
The
super
section
was
just
a
you
know:
a
pseudo
of
depth
and
horizontal
distance.
Some
examples
of
this
here's
a
case
where
you
have
a
buried
conductor,
so
this
is
sitting
inside
of
complicated
medium.
B
B
H
B
G
B
B
B
I'm
simply
going
to
say
that,
then
what
the
process
is
for
the
inversion,
both
with
this
2d
and
any
of
the
three
eat
stuff
that
that
we
do
is
basically
the
following:
that
we're
going
to
take
a
mathematical
model
of
the
earth
divided
up
into
a
whole
bunch
of
uniform
ourselves
and
adjusts
the
values
of
those.
So
we
fit
the
data
and
also
are
consistent
with
some
kind
of
geologic
information
about
simplicity,.
F
B
G
B
That
good,
if
we
look
at
this
example,
which
was
really
kind
of
locked
up
because
of
all
these
nuts
here,
you
see
that
we've
done
the
Burton,
so
has
not
only
recovered
the
object
that
we're
looking
for,
but
it's
actually
done
a
pretty
reasonable
job
of
finding
these
near-surface
numbers.
So
they
have
an
effect.
I
mean
it
might
just
be
geologic
noise,
but
they're
kind
of
useful,
but
the
bottom
line
is
there
is
enough
information
in
these
data,
there's
not
information
and
these
data.
E
B
Okay,
so
that
was
these
are
just
kind
of
like
we're
just
sort
of
stepping
through
the
basics,
but
these
basics
are
actually
so
in
if
we're
up
to
2d
we're
fine,
but
the
world
is
3d
that
makes
things
more
complicated.
Here's
here's
some
3d
scenarios
and
you
know,
first
of
all,
you
know
maybe
you've
got
a
target.
So
what's
what's
the
size,
what's
the
shade?
What's
the
depth?
B
So
there's
a
lot
of
survey,
design,
questions
and
anybody
knows
anything
to
give,
but
it
was
always
concerned
about
survey
design
because
there's
just
so
many
options
of
it.
So
how
do
we?
How
do
we
approach
so?
The
crucial
element
here
is
sensitivity,
so
my
was
just
to
ask
anybody
to
provide
a
definition
within
the
context
of
what
we're
talking
about
for
sensitivity,
survey
design.
B
B
B
H
B
F
B
B
B
C
B
B
So
the
sensitivity
dividing
it
up
into
two
parts
and
we'll
kind
of
do
that
throughout
the
rest
of
the
day,
to
wear
first
of
all,
going
to
concentrate
on
exciting
the
target
and
then
once
we've
done
that,
then
we
can
figure
out.
The
other
thing
that's
really
important
is
coupling
and
that's
going
to
be
the
sort
of
orientations
between
your
target
field.
B
Target
it
looks,
looks
like
this
sort
of
going
into
work
and
we
can
he'll
soon
see
how
the
Hertz
are
getting
deflected
in
this
weather
target
is
located
nine
degrees
on
seven
just
to
see
how
the
curls
are
being
distorted
so
depending
upon
the
orientation
of
target
that
you're.
Looking
for.
Let's
go
jump
tree
and
you
know
its
background
feels
you're
going
to
get
different,
distorting.
B
B
H
B
B
E
F
B
Of
things
here
that
are
really
different,
even
if
you
have
the
same,
you
know
plane
but
depending
upon
whether
it's
more
conductive
from
the
background
or
less
that's
certainly
going
to
so
in
its
summary
expert
for
the
sensitivity
we
we
somehow
need
to
drive
currents
into
that
body.
We
need
to
be
worried
about
coupling
coupling
is
going
to
be
really
important
throughout
the
whole
day,
especially
as
we're
starting
to
talk
about
it,
doctor
sources,
and
then
we
need
to
measure.
B
So
we
want
to
be
in
proximity
to
the
object
and
you
know
use
proper
electrode
orientation.
The
others
at
the
background
resistivity
is
important.
So
those
are
elements
that
you
need
to.
You
know
at
least
address
and
think
about
it's
actually
it's
so
then
we
have
the
question
of
like
survey
design
so
again
we're
in
that
same
country.
If,
if
it's,
if
the
earth
is
1d,
okay,
then
we
kind
of
know
what
to
do.
We
just
do
a
Sally
we're.
B
It's
2d,
okay,
we
can
do
sounding
and
a
profiling
all
right.
It's
a
3d
structure.
However,
then
we
need
to
have
somehow
3d
coverage,
so
people
from
seismic
and
familiar
with
data
me
and
nothing
is
changed
here.
You
just
need
to
illuminate
and
different
different
orientations.
So
that's
first
of
all
the
objective
and
you
have
to
come
to
grips
with
that
like
okay,
what
what
is
it
that
I'm
trying
to
look
for
the
next
is
okay?
Well,
what's
that
background,
resistivity?
B
G
B
Find
something
like
this
so
you've
got
some
kind
of
background.
You've
got
some
targets
in
there
that
you're
hoping
to
find
and
then
you're
trying
to
grass.
Okay
can
I
find
it
it's
my
survey
going
to
be
good
enough,
so
that
I
could
I
could
see
that,
and
you
know,
the
steps
are
really
as
follows.
You
fished
all
I
have
to
you
know
if
I
yell,
ology
physical
properties
to
that
hypothesize
a
survey
and
then
acquire
the
data
both
with
and
without
perhaps
the
target.
This
stays
here
without
the
target
like
Bhoots
target
something
different.
B
B
Is
relative
value
this
and
very
is
at
least
a
certain
percentage,
but
we'll
see
in
most
of
the
experiments,
and
especially
since
you've
got
many
orders
of
magnitude
in
dynamic
range
of
the
data
that
a
reasonable
description
of
noise
is
actually
a
percentage
level
and
then
maybe
something
like
a
floor
value.
So
those
are
the
two
things.
B
H
B
B
First
of
all,
this
is
the
set
up.
What's
the
problem,
we've
got
an
area
that
we're
trying
to
find
the
mineralization
there's
a
geology,
that's
kind
of
characterized
by
this
cross
section
here,
there's
a
number
of
different
types
of
rocks,
each
of
them
color-coded,
there's
some
volcanic,
there's
some
siltstones
and
clays
and
effects
of
minimization
mimic
and
then
there's
appeal
of
it.
But
the
basic
question
at
this
point:
it's
okay:
can
we
find
a
conductive
unit
potential
target
for
mineralised?
B
Look
that's
identified
the
various
rock
units
to
there
and
kind
of
figure
out:
okay,
what's
the
physical
properties,
because
the
same
with
all
geophysical
disturbances,
target
body
that
you're
looking
for
has
to
have
a
physical
properties
that
differentiates
it
from
so
you
got
these
different
units
here,
doesn't
matter
what
they
are.
The
important
thing
is
from
a
conductivity
perspective
that
I
stole.
B
B
F
B
B
B
The
electric
potentials
up
here,
so
they
put
a
whole
bunch
of
electrodes
surface
and
then
they
actually
come
along
and
they
do
a
pull
back
experiment
and
there's
ten
pictures
here,
because
there's
ten
lines
data.
So
what
are
you
telling
us?
Well,
the
red
is
indicating
things
that
have
a
high
conductivity
blue
is
really
low.
You
see
that.
Okay,
these
ten
lines,
no
there's
there's
some
differences.
It
looks
like
it's
rater
to
this
side.
There's
certainly
some
great
things.
G
B
B
To
change
where
the
current
card
so
rather
going
to
be
this,
this
just
flip
things
around.
So
let's
put
this
other
current
on
this
side.
So
now
we
got
kind
of
like
a
dipole
pull
and
now
I'm
at
ten,
more
pseudo
sections,
Oh
right
right.
It's
right
over
here,
so
I'm,
exciting
everything,
a
couple
different
ways:
I
now
have
20
pictures.
There's
only
one
earth
model
there.
So
somehow
what
I'd
like
to
do
is
to
combine
these
guys
and
previous
ones
into
a
three-dimensional
model
by
Kari.
B
B
B
B
And
walk
sort
of
flipping
through
cutting
it
more
south
and
we
plan
view
and
then
we're
going
to
rotate
it
around
and
what's
happening
now,
is
that
the
isosurface
values
are
continually
changed
and
we
end
up
with
the
highest
region
of
conductivity.
So
let
me
just
do
that
again:
okay,
so
here's
the
inversion,
we're
slicing
now
in
you
know,
from
north
north
south
we.
G
B
B
So
that's
what
we
get
out
of
it
and
then
the
next
step
is
well.
What
is
that
all
that
me?
So,
first
of
all,
it's
it's
actually
quite
great
I
mean
we've
taken
industries
that
we've
got
now
a
three-dimensional
earth
model
which
were
really
quite
enthralled
with
and
now
the
question
is
okay.
What
is
it
well,
it
turns
out
this
guy
here.
This
big
conductor
is
a
black
shale
unit.
They
they
knew
that
that
was
around
and
it
was
pretty
easily
distinguished
and
it
runs
north
to
south.
It's
unfortunately,
not
mineralized.
B
B
So
that's
kind
of
where
we
are
a
very,
very
much
a
geophysical
success.
It's
not
the
end
of
the
story
by
any
stretch
of
the
imagination,
because
this
deposit
is
characterized
not
only
by
connectivity
but
even
more
so
by
electrical
charge
ability.
So
in
addition
to
the
DC
there's
also
going
to
be
an
IP
experiment,
we're
going
to
do
that
right
at
the
end
of
the
day,
so
I'm
actually
going
to
close
out
the
day
with
this
particular
survey,
but
show
you
what
actually
happens
when
we
do
the
when
we
do
the
IP.
B
B
Think
I'm
going
to
I
do
have
a
case
history
for
downs
switch,
and
you
got
lots
of
dykes
here,
I'm,
not
sure
where
you
are
with
respect
to
integrity
of
dykes
or
how
all
that
matters,
but
there's
a
lot
of
places
in
the
world
where
you
get
dams
that
are
sitting
up
like
this
and
you
know.
Maybe
there
have
a
little
bit
more
structure
in
that.
That
looks
like
this.
B
B
B
So
these
charges
is
built
up
as
a
little
bit
of
conduit,
but
that's
coming
through
here
then
the
tardis
thing
that
posit
parts
of
money
and
negative
charges
the
other
and
you
can
measure
the
potentials
and,
as
you
go
around
here
and
those
potentials
would
be
reflected
with
these
charges
and
you
can
invert
to
try
to
find
information
out
about
how
the
electrical
currents
are
flowing
through
here
and
ultimately
try
to
get
your
way
all
the
way
back
to
understanding
if
there
might
be
out
a
leakage
pattern.
So
that's
what
this
this
is
about.
B
D
B
Pretty
good
handle
on
things,
yes,
I
might
put
a
a
resistive
layer
in
here.
Then
all
my
currents
I'm
not
going
to
be
able
to
penetrate
that
resistor
there
with
a
DC
circuit.
So
all
of
the
currents
are
going
to
be
sort
of
followed
in
to
the
region
of
above
here
and
yeah.
Your
pair
resistivity
is
actually
going
to
be
large
because
see
this
this
resistor.
B
So
that
means
that
even
a
very
thin
layer
of
something
that's
very
resistive
from
point
of
view
of
DC
resistivity
tend
to
be,
and
just
to
accentuate
that
you're
really
are
only
seeing
that
resistive
layer,
if
you
take,
can
do
the
modeling
without
the
sphere
just
have
that
consistently
get
essentially
the
same.
A
pair
of
recent
students,
so
the
DC
resistivity
experiment
was
fine,
but
if
you
have
a
host,
that
is
not
very
favorable
that
can
completely
destroy
and
then
what
happens?
If
you
have
a
conductive
layer.