Well, thank you all for
coming on what really
what has turned out to
be a lovely afternoon.
So I appreciate your
willingness to sit indoors
for a short time longer.
I'm going to take you to
different ancestral lands.
I'm going to take you to
the islands of Hawai'i,
in particular the big
island of Hawai'i,
to talk about what has
really become one of the most
remarkable incidents in the
recent history of Kilauea
Volcano, and I'll argue, one of
the most remarkable incidents
in recent studies
of volcanology.
This is a volcano that I'll talk
about the eruption that led up
to this part of the event.
This is an eruption that
went on in some for,
for some of you it
was your entire lives,
and for most of us
who study volcanology,
it was certainly our
entire scientific lives,
and this is about the
end of that eruption.
For most of us that was a
really extraordinary event.
We always thought we
could go back to Kilauea
and stick a rock hammer in lava.
And that'll happen again,
but it's not happening now.
So I'm going to talk
about that whole story.
Sorry, I want to just recognize.
This is a project I've
done with several others,
in particular, Yang Shen and
Julie Morgan of University
of Rhode Island and
Rice University.
Also some work by
Xaiozhou Wei, who
is a grad student
at Rhode Island,
and then Adam Soule of
Woods Hole Oceanographic.
I want to point out none of
this, as many of you know,
nothing like this ever
happens in a vacuum.
So here's where we're going.
This is the path I'm
going to take you on.
We're going to introduce
you to Kilauea.
I'm not expecting anyone
knows much about that
or its previous eruptions.
I will talk about the fact-- and
actually it's a little bit out
of order--
I'll probably talk about that
deployment a little bit later.
But the seismic activity that
we were interested in studying,
and a lot about what I'm
going to call the ocean entry.
And you're looking
here at a photo of what
I mean by the ocean entry.
This is where lava
from the eruption
pours into the
ocean at the coast
and makes the big island bigger.
This is how Hawaiian
Islands grow.
My work is focused on things
that are called hydrophones,
hydroacoustic data.
These are just sounds.
I interpret what's going in
the volcano by the sounds
that it makes,
and in particular,
the sounds I'm looking at
are recorded underwater.
So we call those
hydroacoustic, and I'll
talk about that relationship
to the eruption.
But I want to start with a
view of the Hawaiian Islands
that geologists love and
maybe others have never seen.
This is what the
Hawaiian Islands would
look like if you
drained the oceans,
and so really, this
is the geology of it.
These are islands that have
been built up from the seafloor,
and so the parts that
are kind of in green
and a little bit of brown,
that's the part that's
above sea level.
But there is an enormous
amount of interesting that is
underneath the oceans
that we cannot see.
And just for a sense of scale,
this little lump that you
can sort of see right here,
this is called Lo'ihi Volcano.
This is the volcano that will
be either the next island
in the Hawaiian
chain or will simply
merge with the big island
and make it bigger.
And just to get
a sense for that,
that's about the size of Mt.
Baker.
So these are huge.
These are enormous,
enormous edifices.
Second thing I want to
call your attention to,
and it's right up there, where
I can't reach, so bear with me.
Up here, you see all this
debris on the seafloor?
All that stuff is half
the island of O'ahu.
All that stuff is half
the island of Moloka'i,
and it turns out that,
at times in the history
of these volcanoes,
they may break in half,
or enormous portions of
them might slide off.
A lot of the debris you see on
the sides here are landslides.
So one of the things
that really interests us
about these volcanoes is trying
to understand how they form
and how stable their flanks are.
These do not happen often,
for which we are grateful.
But they can be pretty
amazing when they do,
as long as nobody is
anywhere close to a coast.
So what I'm going to
do now as I'm going
to zooms in on the big island.
The big island here is
made up of five volcanoes.
We are interested
in Kilauea, and I'll
come back to that in a bit.
Well, actually, we'll
come back to it right now.
When we think
about Kilauea, I'll
outline for you
where it is on land,
but what I'm
pointing out here is
that actually the bulk
of Kilauea is underwater.
So all the stuff you see
kind of stretching out
there towards the blue, which
is the deeper part, that's
all part of Kilauea.
So if we just look at,
zoom in on that part,
there are structures that
I'm going to mention.
So you can see the outline
in the solid black.
That's the boundaries of what
we think of as Kilauea Volcano.
I'm going to be talking about
places like Halema'uma'u which
is the caldera at the summit.
I'm going to talk a little bit
about Pu'u O'o and the Puna
District.
This area here,
all the part that's
underwater, it's called
the Kilauea South Flank,
and this is an area
that we know is slowly
being moved to the south.
It is slumping in this
direction, and a lot of people
have expressed
concern that this may
be where the next big
slide is going to happen.
So one of the reasons we
study it is to say, well,
is that the case?
So in 1998, I was involved with
a project, where we went out,
and we did what's called a
active source seismic survey,
where we basically echo
sounded into the subsurface
to see the structure.
And you're looking here
at a cross section,
where that's the
sea floor, and this
is you're basically going
underground, along this line.
And you can maybe see
there are these sort
of folded packages of debris.
This is sediment that's
sloughed off the big island
and then got snow plowed up.
If you can imagine taking a plow
and pushing all this debris,
and it kind of back
rotated like that.
So we took data that allowed
us to make this picture
and actually found
it really reassuring.
Because all this stuff is
back rotated and folded,
that tells us this
whole bench, if anywhere
is sliding backward,
and it's holding
that whole flank in place.
So this was really
reassuring to us
that we are not about to
see a catastrophic landslide
off the South Flank,
but nonetheless, we
keep an eye on it
for that reason.
So keep that in mind.
We're going to move
forward, and I'll
show you a little
more about where
things stood in early 2018.
May I ask a question?
Yes.
Bounded by the red?
Just that South Flank area, the
area that we know is mobile.
We don't really know how
much off here is mobile,
just no data.
So that's the area that
we know is constantly
building up and moving.
Yeah, and do holler out
questions if you've got them.
So starting in 1983, an
eruption began at Kilauea
at what's called
the Pu'u O'o Event.
Some of you may have
been out to Kilauea
during the time period
of this eruption.
That's where it continued
to erupt, up until 2018.
So Pu'u O'o was responsible for
the production of an enormous
amount of lava, the destruction
of a couple of communities,
and it looked kind of like this.
This is looking down
into this roiling lava,
this little lava
lake at the pu'u.
Pu'u means hill, so it's
a little hill right there.
So that was from 1982, did a
whole bunch of variable things,
and in about 2008,
a new eruption
began, or a new part
of the same eruption,
up at the summit of Kilauea.
And Kilauea's summit
has this thing
that looks kind of like
a big old thumb print,
and I'll zoom in.
It looks like somebody
stuck their thumb down.
The whole thing is
sunk in a little.
We call that a caldera.
Within Kilauea's caldera,
there's another little pit
called Halema'uma'u, and that
is where the goddess Pele,
who's the goddess of the
volcano, makes her home.
This is an area that
was an active lava
lake for over 100 years, in
the 1800s and late 1700s.
In 2008, another pit
opened up in Halema'uma'u.
So you went to a pit,
in a pit, in a pit,
and you can see the
small one there,
and you might see that it
too had a lava lake in it.
So from 2008 on, we had two
places actively erupting
on Kilauea.
So I'm going to walk you
through what happened in 2018.
It was kind of business as usual
for the bulk of the spring.
In late April, there were
overflows of the lava lake
in Halema'uma'u.
That had happened
before, but you
can see this is
the bigger crater,
and there's just stuff flowing
all over the bottom and,
again, not that surprising.
But something somewhat unusual
happened a couple days later,
when the floor
Pu'u O'o collapsed.
Now, it was a really,
really ugly day there.
So you can't see
much, so I'll try
to show what it looked like.
This is a previous
collapse of the pu'u.
It's going to get kind
of hazy for a bit.
We'll go past that.
It's a time-lapsed video.
You can see lava flows pouring
on it, but what happened
later is this.
And so this was a
couple of years earlier,
but it happened
again in later April.
And that was all very
exciting, but what happened
after that was different.
So we're back to a
map of the big island,
and this is a figure that was
taken from some satellite data.
This is done by
Bridget Konter-Smith
at the University of Hawai'i.
And when she looked at these
data, what she did was to say,
what part of the land has
moved toward the satellite, up,
and which part has moved
away from the satellite?
So we're looking
down from space,
and every place
it's blue has sunk,
and every place
that's red has risen.
So after this collapse of the
pu'u, which is right here,
we see this inflation
of the Puna District.
And what that looked like on
land, somewhere in that area
were cracks in the ground,
and that was a curious thing
to see.
This was watched
for several days.
These cracks got bigger.
Steam began coming out of
the ground, and on May 3rd,
an eruption began in the
Leilani Estates subdivision.
And so this is,
basically, you would
walk near people's backyards,
and there was lava pouring out.
This is an area that had
many hundreds of homes.
So again, this is May 3rd.
So we now have taken lava from--
well, we had lava at Pu'u O'o.
That's gone.
Now, we're erupting in Puna,
and the next day, there's
a 6.9 earthquake.
That's larger than
Nisqually, for those of you
who felt that, you know good
deal larger than Nisqually.
And what it does is, you
can see on the arrows here--
this is from work
by Liu, et al--
it pushes the whole
flank that way
which is always
interesting to us.
Now, we know these
have happened before,
earthquakes in this area,
but it was kind of curious
to see that this went on.
So this big earthquake
occurs, and I'll
show you where those earthquakes
were, with respect to the South
Flank.
So here we are, back
to that south flank,
and this is the
6.9, and these are
all the earthquakes that took
place in the week afterwards.
And what we see is that
there's earthquakes
that are all along that red
boundary that Dennis pointed
out.
Which kind of made
us a little worried,
just because we hadn't
really seen earthquakes
out there on that
bench that we know
is holding the flank in place.
So we thought, well, that might
be something we want to study.
So we'll just keep
that in mind, and I'll
walk you through the
rest of the eruption,
and then we'll
come back to this.
So this is going on.
Several days later, even
more weirdness occurs,
and there's explosive activity
at the Kilauea summit,
first time there's been
explosive activity, since 1924.
There's now a ton
of lava pouring out
in the Puna District, and
there are many, many fissures
that are opening up and
opening up and opening up.
And you can see where all the
streets are, and here's where
the lava is, and we're
up at this point.
When this figure was made, we're
up to 23 different events that
have opened and poured lava
out, and most have closed again.
And it's pouring into the ocean,
and finally, it all kind of
collected at fissure
number eight,
and that remains the
locus of activity
for the remainder
of the eruption.
From there, lava flowed
from fissure number eight
about eight miles, all the way
through these subdivisions.
This photo right here,
this is the lava flow.
This is the Puna
geothermal venture.
This is a geothermal
power plant.
You can understand why
you would tap this area
for geothermal energy.
At this point, however, things
became a little hazardous,
and they shut the plant down.
But just for scale, that
plant is probably about a half
a kilometer across, so
a quarter mile or so.
So that's a very
large lava flow,
and it's extending
eight miles to the sea.
As it extended there, it
went through the communities
of Kapoho and Vacationland,
and in the end,
over 700 homes were
lost to this eruption,
and this whole bay is gone.
That bay is now filled in with
activity that looks like this.
As the lava flowed
into the ocean,
it developed these
solid lava flows.
It fragmented.
We'll talk a lot about
that, and where we stand now
is a map that looks like this.
And it's hard to see
from where you are,
but I'll try to point out,
there is a dashed line
all along here.
That's the old coast.
We've added about 900 new acres
of land to the big island.
It is the bigger
island now, and that's
the part that interests me.
Because first of all, we
went out and mapped it.
We mapped what the new
bathymetry is like.
So bathymetry is
topography underwater.
And when we did
that, we compared it
to previous bathymetry, and
what you're looking at there
is that same coastline.
There's the dash, and
everywhere you see colors,
we've measured how much
new material there is.
And we are easily over a
kilometer offshore here,
and we've got still
200 meters of material
that's been emplaced.
And overall, it looks
like at least 60%,
maybe as much as 65% or 70%, of
all the lava that erupted here
went offshore.
This is an offshore eruption.
We focus on the land stuff,
but really, the activity
happened off there.
Further, this photo
that was taken, again,
that's about a kilometer
offshore, that's a lava flow.
Lava just headed
on into the ocean.
So everybody who
says, can't we just
spray these things with a hose?
Well, the ocean didn't stop it.
Right?
So this was a really
pretty impressive event.
So this inspired in us
a bunch of questions.
Right?
We wanted to know what effect
that 6.9 had on the South
Flank, whether it caused any--
whether there's any increased
hazard from landsliding.
We don't even really know
on what fault it occurred.
Those are details I'm
not going to get into.
My colleagues, Yang
Shen and Xaiozhou Wei
are working on that problem.
My real interest is how
the lava-water interactions
contribute to the
growth of the coast
and the stability of the flank.
So with all these questions
in mind, my colleagues and I
wrote to the National
Science Foundation and said,
we've got one chance at this.
We've got one opportunity.
Let us go out there,
and they funded us
via what's called
a rapid response
grant to go put seismometers
on the seafloor offshore.
Our goals were to
constrain the locations,
to locate where these
earthquakes occurred offshore,
to record the
aftershocks of that 6.9,
to understand its failure,
and to characterize
the sounds and the shaking from
those lava-water interactions.
We did this aboard
the research vessel
Ka'imikai-O-Kanaloa which is
a University of Hawai'i ship.
This is me with
two of my students,
who I brought to sea with me.
Kevin Lally, on the left, was
my graduate student at the time.
Lena Gibbs is an undergraduate
in the geophysics major,
both here from Western.
The KOK, this vessel, this
was its penultimate trip.
It was mothballed
soon thereafter.
We know why.
All I can tell you
is if it wasn't
necessary for that
ship to float,
it hadn't been fixed in years.
So we got to enjoy
some adventures.
It was not just us.
Each of the PIs on the project
brought students with them,
and we also reached out to the
University of Hawai'i and said,
who wants to come to sea?
We've got space, and so
we had a graduate student
and two undergrads from
the University of Hawai'i
who joined us.
We also had an engineer
from Scripps Institute
of Oceanography who is in
charge of the instruments,
and I will tell
you, Yang and Julie
and I sat back and watched.
They were the
heroes of this trip.
So Martin taught the
students all about how
to construct these instruments.
So these are the ocean
bottom seismometers.
So the students put these
whole things together,
prepared everything for launch.
Once they're all
built-- actually,
this is the inside of it.
I want to point out the two
instruments that these carry.
We're looking down
on the guts of this.
This is a seismometer.
It measures shaking
of the ground,
and a hydrophone
measures shaking
of the water which is sound.
So both of those are
co-located in this instrument.
This is what it looks like
as we're launching it.
That metal plate is a
weight that carries it
to the bottom of the
sea, and the flag
and the other
little things on top
are there to tell us where
it is when it returns,
and we can find it again.
The yellow is all
flotation, and so this is
what the launching looks like.
So we put the instrument,
basically, just
leaned it overboard.
Oh my goodness, you might need--
that's like making us more
seasick than the actual cruise.
But you'll see, they're
just going to disconnect it,
and it drops to the
seafloor, and then
we do a little work to
measure where it was.
We come back two months
later, and we call to it.
We send it a little
acoustic signal,
and we say, drop your weights.
Drop your weights.
And it drops that weight,
and it's now positively
buoyant and floats to the
top, where we pick it up.
So yikes, let's move on.
Shall we?
That was brutal.
All right.
So here's the network
we put out there.
So these are where
the earthquakes
were that we were chasing,
and all the triangles are
where we put instruments.
There are two sad red triangles.
This one just didn't record.
We don't know why.
It just didn't record, and that
poor sucker never came back.
And it is a little close
to the ocean entry,
and there is a
non-zero possibility
that it is now part
of the big island.
But I really cannot say why.
All I can say is that it
did not come back to us,
but the other ones did.
With the star up there, that
is where lava was actively
flowing into the ocean.
So these were the signals
that we can record.
Now, I want to point out that we
put the instruments where they
are here, because we were trying
to surround the earthquakes we
expected to get.
These were the
earthquakes in May,
and it took us about six weeks
to get instruments and get
a boat.
So by the time we got out
there, the seismic activity
was a little different, and
these were the earthquakes--
if this will
change-- that we got.
So happily, things
offshore had tapered a bit
from the stability of
the flank perspective.
There's a lot more on land.
We'll come back to that.
These were just the
earthquakes that were located
with the instruments on land.
This was the Hawaiian Volcano
Observatory's perspective.
Xaiozhou Wei is working
on this right now,
and I apologize, the quality
this figures a little poor.
But these are the earthquakes
that he has detected,
and you can see there's
way more offshore.
If we go back to what
we thought was there,
the Hawaiian Volcano Observatory
only saw maybe 50 offshore,
and Wei sees quite
a few hundred.
So we know that our having
instruments out there
is going to give us a much
better picture of what
was happening, just
work in progress.
Now, again, my big
interest is this,
is where the lava
flows in at the coast.
So again, this is a thing
that grows the big island.
This is the process really
by which all of these islands
have formed over time.
I'm going to show you a photo.
I took this photo on a
helicopter overflight the day
after our cruise, and
so a couple of things
you can see here.
First, that lush green Hawai'i
that you saw in previous things
is buried.
This is all under
lava right now.
The lava itself, you
can see it's steaming,
but it's actually a
fairly passive process.
It's just flowing
into the ocean,
and because it's
a passive process,
there's a tour boat that
feels pretty confident going
close to the coast right there.
So this is a tour boat that went
out there every day for scale,
that's about 40 feet long.
So it gives you some
sense of what we've got.
Now, this again is July 14.
So the next morning, my student
Kevin went on that tour boat
to go see what it looked
like from that view,
and this was Kevin's view.
And once again, I apologize
for the shakiness,
but this is the exact same area.
I'm really sorry.
This is shaky, but
you can get an idea.
It was really different.
Something was very, very
significantly different
on this day.
Some of you might
hear him go, whoa.
So highly explosive,
substantially more interaction
with the water.
So I'm going to show a bunch
of figures that look like this.
Now, let me explain
this for a second.
These are things
called spectragrams,
and this is a way of
looking at seismic data
in a way that tells us a lot
more than just the wiggles.
So on the top--
there are two different
stations here--
this is a station very
close to the ocean entry,
and this is a station
much, much farther away.
Each one shows what we
call seismogram on the top.
That's showing, basically,
how the water shook.
It's basically was it
pressured or pulled away?
Right?
Compression rarefaction.
And we can see, there's a pretty
strong signal at that part
there, because we see
the bigger amplitude.
It was like whomp, whomp,
in the water, like that.
The bottom panel shows
another perspective on things.
So earthquakes
are, in this case--
this again is acoustic.
This is sound.
Earthquakes do the
same thing, in that,
they have different frequencies.
There are high notes,
and there are low notes.
So I think of this as the
Earth playing us a symphony,
and this figure
shows all of these.
This, the vertical axis
here, is telling us,
low notes on the bottom,
high notes at the top,
and then the colors
are which are louder.
So here, we see there's a
lot of very, very strong.
The warmer colors,
pinks and reds,
are loud, strong,
very low frequency.
Right?
We've got timpani going
here and giving us
this baseline for
the whole thing.
And then occasionally,
we've got things
that are much higher frequency,
and that sounds like a crack,
like that.
This very strong thing
here is very low frequency.
That's an earthquake.
When we get closer to the ocean
entry though, first of all,
it's a lot noisier.
There's a lot more
high frequency stuff.
That's a lot more
powerful, and that's
just crack, crack, crack,
crackling all that,
and that we think is the sound
lava interacting with water.
And we can tell that, in
part, because it's very loud.
Again, all those
warmer colors are
because there's tons of noise.
Right?
They're near the coast,
but we also know this.
This is a figure--
so we took this from sea.
On July 11 at noon, this is
what the coast looked like,
and you can see some
steam on the right side.
And you can see some
actual smoke here,
and I really mean smoke here.
Volcanologists get all
fussy when people say smoke,
because people often
think ash is smoke.
Ash is rock.
This is a burning building.
This is actually the
destruction of a school
that was in this area.
Two hours later,
there is a new area,
where steam is coming,
because the lava
flow that destroyed that school
has now made it to the water.
What we see on the
instruments at that time
is a dramatic increase
in the amount of noise,
when that thing hits the water.
And this is the
station closest to it.
These are all much farther away.
So we can see, when
the lava hits water,
this is what it sounds like.
So we can use this now as
a little bit of a proxy
for when is lava flowing in,
and is it flowing in violently?
This is just a little passing
thing that excites me.
Maybe nobody else cares.
One of the things, when
we're looking here again,
these same kinds of signals.
And what you might notice,
if you look carefully here,
are these kind of
horizontal bands,
and you can also sort
of see them here.
Quiet note, loud note, quiet
note, loud note, like this,
and that sounds like a chord.
It's a harmonic.
So you're hearing
octaves being played.
Sometimes, when
we hear that, that
is actually the
volcano being resonant.
In this case, it's not.
In this case, it's an
interference pattern.
We have sound going
directly to our sensor,
and we have sound bouncing
off the surface of the ocean
and then hitting the sensor.
And depending on how the
source receiver geometry,
sometimes those frequencies add
up constructively and get loud.
If that path, though,
is a little bit longer,
or if the frequency is
basically half a wavelength off,
they cancel.
And we can use
that pattern to see
how far away the source was.
We can find out that
source receiver geometry.
And what's cool about
that is, most of the time,
in a lot of these
signals, we don't see it.
We didn't see it at
all in the last figure,
but now we see it,
which tells us it's
happening somewhere different.
And we can model which
frequencies would be loud
and which would be quiet.
So we can see where those
sources are coming from.
Also, a work in progress, I've
done this on another volcano,
haven't yet done it for Kilauea,
but that is our hope is that
we'll be able to tell where
that lava is flowing in the part
of the ocean that we cannot see.
That's something that's
moderately easy to model.
Sometimes, these
things get really loud.
So now, we're looking
at the full network.
These are the two
stations closest,
and you can see that
this is super loud.
Both in very low frequencies
that you can barely
see where you are,
and then some that
are cracking across
the whole spectrum.
And even our distance
stations, some of them
are picking them up.
Some don't.
Those little low frequency
pulses you see on all of them,
those are earthquakes going on
in the background all the time.
This particular one,
we know what this is.
This was recorded the day
after Kevin got off the boat.
You saw the day I took a
photo, and it was quiescent.
You saw Kevin's video, from
when he was on the tour boat.
The next day, that tour boat was
out there, when this happened,
and that's what happened
to the tour boat.
So there was a highly
explosive event
that smashed the roof of the
boat and injured 23 people.
One was a Western
alum, and we're
trying to work a deal, where
she's going to bring me
her photos, and I'm
going to let her see
her rocks under the microscope.
That's our goal.
We've been having
trouble connecting,
but we're going to do this.
So it would be really nice
to know when this thing is
acting explosively.
So this one happened
at about 5:30
in the morning, Hawai'i time.
Two hours later, we saw that
monstrosity, and that was huge.
This is an enormous signal.
Now, I'm not sure if the next
photo I'm going to show you
is this big sucker or
if it's just this one
here, because I don't have
a good time stamp on this.
But there was a boat
out there at the time,
and he took this photo.
That is an enormous explosion.
We don't see very much of
this, and in fact, that
was the largest explosion
we recorded during our time.
But potentially, it
can tell us, again,
what do lava-water
explosions sound like,
and we can listen
for them and start
to recognize better, when
there's no one there,
what happened?
So one of the big questions
that I have is, basically,
why is it explosive
sometimes, and why is it not
explosive sometimes?
Why are there times we see
tons of noise and times that we
don't?
So this is actually
an issue that's
been studied for a
long time, and I'm
going to take you back
to 1997 and a paper
by Mattox and
Mangan, where we're
looking at, again, a
cross-section into the ground.
And they said, there are
times-- we have lava flowing
into the sea all the time.
This was back in
the Pu'u O'o days.
But occasionally, we
get these landslides,
and there's a very
large flux of water--
excuse me, of lava
into the water.
And when there's a lot of
lava, it gets more turbulent
and mixes more water
in, and it explodes.
Alternatively, you can
just of fracture that thing
and pour water in the top.
So their hypothesis was that
more lava equals more explosive
at kind of a core level.
So my thought is that, OK, if
more lava is more explosive,
I think I have data
that show how explosive
it was over the whole
time we were there,
because I think we can hear
when it's more explosive.
So I'm just going to show a
first cut of, if it's loud,
it's explosive, if
it's quiet, it's not.
And we look at over
like a couple of months,
and you can see times
where the noise is loud.
This is basically
loudness, not loud.
Right?
Times when it's
really loud, times
when it's quiet, times but it's
loud, times when it's quiet.
We see these oscillations
that I suspect
are associated with when is
it explosive, when is it not?
And I'll bet you can see
where the eruption ended,
and then there was
no noise after that.
So I went to present this at a
conference, in San Francisco,
in December, and this was
one of my summary slides,
and I was all
excited to show this.
And I'm flying down,
and I open my email,
and there is an alert of
the new paper that's come up
that relates the
strength of seismic
shaking to the amount
of lava coming out.
Well, I was like, let's
take a look at that.
So I looked at that
paper, and they
did kind of the same thing.
They looked at the
strength-- they
were looking at seismometers
on the ground, how
much the ground shook.
I'm listening to how much
is shaking in the water,
and this is not something you
have to worry too much about.
But what we basically see
is there are times when
there's a lot-- this
is the seismic stuff--
a lot of shaking and then
a lot of lava coming out.
As the ground is
shaking more, you
can see the level of
lava rise in the tube
and then back off again.
So I added their
seismic data into mine,
and then for good measure, I
added one of my hydrophones
that was far away
from the ocean entry.
And so what we've got,
here are my hydrophones
that are close to the lava.
This is the one that's
far away from the lava,
and it doesn't see
those surges at all.
So it's another
good confirmation
that what we're looking
at is lots of noise,
when there's lots of lava.
And then you see
the seismic pulse.
It's in a terrible color for
this background, my apologies.
I was mostly trying to avoid the
red/green issue for people who
cannot distinguish.
But what we can kind of see
is, where they have peaks,
a little bit later,
we often have peaks.
Now, it's kind of arm-wavey,
I'll fully concede.
But there is a big
peak in how much
the ground shook, which
we know is correlated
with how much lava flows.
And a few hours later,
I see a surge in noise.
These two are a
little harder to tell.
There's a little bit of an
increase, but it's vague.
This one, increase a
little vague, nice pulse.
Six hours later, I
get a surge in lava,
or I get a surge in noise.
They get a big one, I
get a surge in noise.
So every time the ground--
so it shakes on land,
give it a little while,
and it shakes in the water.
And I think what
we're seeing here
is the amount of time it takes
the lava to get to the coast,
and actually, we can use
this as a bit of a proxy
for how rapidly that process
could move, if this is correct.
So I want to tie this stuff
together a little bit.
So the lava is coming out of
fissure eight, right here,
and it is flowing eight
miles, around here,
and this is where
it's pouring in,
at the time that I'm
paying attention to it.
So that process takes hours.
It's also kind of
an open system.
So it's not clear
that all the lava
that comes out of fissure eight
is going to wind up there.
Some of it gets diverted.
Some flows to the side.
So it's not clear,
more lava comes out,
more lava hits the ocean.
There are some transitions that
can also happen in the middle,
but we do know that this thing,
this connection, is there.
So there's an important
issue, though,
that comes with this of why we
have these surges, why there
are times when the
ground shakes more,
and why more lava comes out.
So we have to think now about
where the lava comes from.
And so this was work that was
done by Anderson and others--
actually came out on the same
day that other paper did--
about how these
things are connected.
And this was actually
fairly well-known
from people watching
at the time.
What we think is, if you were
to look underground here,
here's this summit.
This is where all the magma
hangs out, most of the time,
and it gets squeezed
underground.
It used to go up to Pu'u O'o.
Now, it heads out to the rift.
We also saw something
pretty extraordinary
going on during this eruption
that links that process to what
we saw.
What you're looking
at here are the number
of earthquakes
occurring, recorded
every hour, over the
course of the eruption.
So you can see, and this
is actually probably
earthquakes over about magnitude
2, maybe some over magnitude 1.
There were so many
earthquakes happening
that this is a really small
subset of how many actually
went on.
They just could not keep
up with processing them.
But what you see is that there
are a lot of earthquakes,
and then it tapers.
There are a lot of earthquakes,
and then it tapers,
and that cycle went on.
It's a little familiar with
what we were just looking at.
Furthermore, all those
yellows, those are earthquakes
that were magnitude 5 and
above, and if we look carefully
at the timing of this,
what you see is this.
Lots and lots and lots
of earthquakes, boom,
magnitude 5, quiet.
Builds up again, lots
and lots and lots
of earthquakes, boom,
magnitude 5, quiet, and this
happened 63 times.
63 magnitudes 5's hit
the summit of Kilauea.
Let me show you
what was going on.
I sure hope this sucker goes.
OK.
So this is a time lapse
video of Halema'uma'u crater.
There's the explosive stuff.
Now, I want you to
watch the edges.
So what we have is
lava pouring out in
surges at the coast and
the summit collapsing.
And it turns out that every
time there was a collapse,
there was a pushing of lava all
the way down to fissure eight.
And after that, there was
a flow out to the coast.
So we had a plunger,
and we had it--
there is an immediate
connection there.
It's like turning on a hose.
You turn it on at the faucet, it
immediately comes out the side,
because it's full of water.
So same thing here,
it's full of magma.
So that's what Halema'uma'u
used to look like,
and this is what
it looks like now.
The Jagger Museum that
was up there is closed.
The Hawaiian Volcano Observatory
has had to move to Hilo.
That area is no longer-- a lot
of that area is not occupiable
anymore, because
everything was damaged.
So I'm going to show, in
summary, all the processes that
went on together.
And so this is an animation
that was put together
by Nathan Becker at the
Tsunami Warning Center.
What you're going to see are
earthquakes that pop off,
and yeah, you can see this is
like background earthquakes
happening all the time.
We're in early April.
So the earthquakes occur
and then fade away,
just so they're not
blocking your view.
We get little swarms like
that, from time to time.
This is background
seismic activity.
So the lava lake is going
to overflow in late April,
and then we're going to have
the collapse of Pu'u O'o.
And then you're going to see
the seismicity propagate down
the rift, right here.
We're going to get
a 5.4 and a 6.9,
and you can see that
whole flank lighting up.
Now, you're going
to see a lava flow
start to pour out at the coast.
There's a lot of seismicity
associated with this at first,
because we're cracking new paths
for those fissures to open up.
But after a while, once
those fissures are open
and everything concentrates
at fissure eight,
everything's hot.
Lava doesn't have to
break the ground anymore.
We no longer have a lot of
earthquakes out in the Puna
area.
What we do have,
you can see now--
it's written here as explosions.
Nathan made this a
little while ago,
and I haven't replaced
it with a better one.
We didn't know what those
collapse events were,
for a long time.
People were calling
them explosions.
Now, we know there
were collapses.
Every day, there's a
magnitude 5 at the summit,
and they keep going
and going and going.
So we're in June now.
Again, the lava flows.
You can see it pouring out
there, building the big island.
You can see where it's
covering that new Kapoho bay
and building out that
new part of the coast.
We're into July.
We still have-- again, a sticky
connection to the video--
but you can see these things
that are occurring still
at the vent.
But we've only got
probably six or seven more,
and then we're going to
just watch at the summit,
as we come toward the end.
We were watching these
every day saying,
there should be a 5
occurring anytime.
There should be a 5
occurring any time.
And one day, I
said to my husband,
there should be a 5
occurring any time,
and we watched, and we
watched, and we watched.
And it stopped, and that's
what it all looked like.
That was the whole sequence.
And since that time--
those are just the
eruption, the final features
that were there--
so since that time,
there has been
no lava on the surface
of Kilauea Volcano.
For the first time in
a very, very long time,
it has been totally quiescent.
I have hypotheses about
when it will start up again,
but I'm not sure how
popular they are.
I think it'll be
probably a decade,
and that's just based on we
had very, very similar event
happen, in 1996.
But on that volcano that was
underwater, the one that I
said was the size of Mt.
Baker, it did this
exact same thing.
But nobody saw it,
because it was underwater.
And we recorded it,
but since then, Lo'ihi
has done almost nothing.
Since then, it's been
a couple decades.
Now, Lo'ihi is not
as active as Kilauea,
but I think that kind
of summit collapse
really disrupts a
magmatic system,
and I suspect Kilauea is
going to be quiet for a while.
So where we are now with this--
if I can get to this-- so this
was an unprecedented event.
It was unprecedented in
terms of the amount of lava
that flowed out, the number
of structures destroyed,
and people displaced, again,
700 structures destroyed.
The summit deformation, that
collapse of Halema'uma'u, none
of us, even now, can believe it.
It was such an enormous event
in the life of this volcano.
I'll talk about that one
more in one second again.
It's the end of 35 years of
continuous eruptive activity.
We've seen these really
interesting explosions
that we think we can
use now as a window
into these long term
processes, even when
nobody was there look at it.
A side note, when the Pu'u O'o
rupture was going on, pouring
lava into the water, it was
constantly building a bench
and collapsing,
building and collapsing,
and there were landslides every
day underwater, little ones.
We saw none at this one.
So there's something
very different about how
the lava poured in.
That is another direction
that our research will go,
and we think that
potentially there is
this connection between these--
we know there's a connection
between the collapses
and the lava coming out.
I think we can also tie that
to how much lava flowed in
and try to get a sense
for when is it explosive?
What does it take to make
these things happen quietly
or explosively?
The last thing I
want to say, I said
that things were really
different at the summit.
The other thing that's happened
since this time is that that
crater is now so deep,
in Kilauea at the summit,
that it's now below
the groundwater,
and water has been
flowing into Halema'uma'u.
If a little bit of water flows
in, and magma rises again,
it'll vaporize the water,
and that won't be a problem.
If a lot of water flows
in, if we have a real water
lake at the summit,
and magma comes back,
then we have the potential
for highly explosive activity
at Kilauea.
And we know that, at other
times in Kilauea's history, most
recently the year 1790, it has
had very explosive eruptions.
But no one has understood
really how that happens,
and we may be seeing
that for the first time,
but time will tell.
So that's where we are.
I would be very happy
to take questions
about any of this stuff.
Thank you.
[APPLAUSE]
Dennis, yes?
The lava that erupts
on land, and then
moves down to the ocean,
it must get much cooler,
versus the lava that actually
merges directly into the ocean.
Right.
Right.
OK.
So this is a question about
how that changes behavior?
Yeah.
OK.
So Dennis's question is when
the lava flows out for a while,
it's going to cool
down, so versus
if it's coming right in there.
So could the temperature
also impact that?
So when lava flows--
it's an excellent
question-- so a lot of it
just has to do with how
insulated it is as it flows.
And a lot of what
we see on Kilauea,
when we get out to the
coast, we actually largely
did not see big lava
flows on the coast.
It would insulate itself.
It would freeze on the top
and come out through tubes.
So if we go back here to--
there's a figure that I'll show
that kind of makes that case.
OK.
So you might be able to
see in this figure that--
sorry, that's another ocean
entry from years past.
So you can see this is
pouring out of the ground.
So it's actually been
pretty well insulated,
and so we've seen this on
Pu'u O'o for a long time.
Lava would flow out
from underground,
and you would take a sample,
or take a temperature sample,
and it's still 1,100 degrees.
So if it's liquid, it's got
to be over 1,000 degrees
if it's basalt. So we know that,
and if it gets much cooler,
it freezes, and it
doesn't make it.
So probably not a
huge difference,
but I could be wrong about that.
Other questions.
Yes.
The cross section that you
had from the initial summit
and then the one
now, [INAUDIBLE]
I don't, others do, that was
in that paper, and the volume--
so Zach's asking about this.
I don't have that
number in front of me.
There is a volume estimate,
and it correlates pretty nicely
with how much lava came out.
Not perfectly, but there's
also a lot of landsliding
and things like that that
slough off and all that.
But yes, it correlates
pretty well.
Do you know where the
water table is on this?
It's very low right now.
The water, I don't know where
the water table exactly is,
but I know that water
now is percolating in,
and we've got a few--
I don't know if we know
exactly how deep it is.
I would guess it's a
couple, five meters deep.
So still pretty low, highly
acidic, it's pretty cool.
They have to fly a drone
over and take a sample of it.
So they've been experimenting,
and in fact, another Western
grad--
Angie Diefenbach who did
her masters with us here--
is now the primary person
making all the drone science
happen at the Hawaiian
Volcano Observatory.
In fact, not only was she
responsible for showing
how you could get
estimates of lava flux,
and you could measure all the
stuff that you couldn't get out
there to see.
But at one point,
at night, there
was a man whose house was
largely surrounded by lava,
and he didn't know
where to go to get out.
And they had a thermal
camera showing where he was,
and Angie flew the drone over.
And they directed him
to follow the drone,
and she got him to safety
and saved his life.
Wow.
Yes.
Do you mind if I take a
picture of the slides?
Oh, no, go ahead, totally.
And all of this stuff, all
these really cool photos,
most of the things
like this are available
in the Hawaiian Volcano
Observatory's website.
It's a USGS website, and some
of those photos are mine.
I'm going to share
them with the library,
but also, HVO has amazing
photos on their website.
Anything else I
can answer for you?
My wife and I were there in
April, [INAUDIBLE] April 30th.
So this is-- yeah.
It took a while
for it to collapse,
so you'd have to
be there for a bit.
But if I can make this--
again, I can never tell
what their videos--
they have really long
intros, so I'm never
sure if I've hit
play properly or not.
Let me just--
I'll just show you--
if I can make this work.
Jeez.
This is one other
video, and again--
come on.
There we go.
I know our videos are terrible,
and if it's making you seasick,
just close your eyes, but we'll
see if we can get this to go.
So if this video will
work, they fly over.
You can see good views of
the water pond, in theory,
are there.
They give us a lot
of time to read.
There we go.
So this is Kilauea Iki.
This is another little crater
off to the side of the caldera.
This is the main caldera.
That's a place called
the Desolation Trail,
people might have hiked,
if you've been there.
Here is the new Halema'uma'u.
Seismic station fell
in there somewhere.
So all of this is
a new collapse.
This is certainly
far deeper, and when
they come around the side,
you're going to briefly see,
I think--
let me see if we can get to it--
a portion of the road
that is now in the crater.
Yeah.
Here's the road.
You can't drive
around it anymore.
Nope.
You can't drive around.
They actually haven't let
you go into the caldera
for a long time.
You can see the pond here.
OK?
So it's a little deeper
now but not much.
Yeah.
My husband and I
went last March.
We actually got to drive
into Leilani Estates
and walk on fissure
eight, and it was amazing
how there were houses on
one side of the street,
and the other side
of the street,
the houses were all burned down.
Yeah.
Yeah.
And the street just
ended at the lava flow
across the end of the street.
One of the things that you
saw, which is fascinating,
is you would see the lava flow.
And if you look
down from the top,
it'd be perfectly lush
on one side, and all dead
on this side.
Because the fumes would go
in the direction of the trade
winds.
Trade winds would blow the
fumes from the lava which
produces acidity in
the water and the air,
and that acid killed off all
the plants that didn't burn.
When we were there,
one of the things
that the rangers said to
us-- we were at the overlook,
looking at the side of it.
And at that time, the
lava was backing up
and they said, oh, you came
here at the perfect time,
because sometimes you
couldn't see the lava.
That's right.
And I said, why?
They said, well, it's
plugged up down somewhere,
and it's raising it up.
Yeah.
I said, oh, what's
going to happen next?
And they were like, well,
we don't really know.
The plug might just melt,
and it'll all flow out,
or it'll go somewhere else.
Right.
And I was curious
your reaction to this.
I think that's exactly right.
That was always-- it's
kind of always the case,
volcanoes do things that are
predictable, until they don't.
And they do tend to
be creatures of habit,
so we do tend to know, well,
we've seen this happen before.
But largely, we say, oh,
we've seen this happen before.
When that thing changes,
well, then, we know.
So that pressure that we saw
build that caused the lava
lake to overflow like that,
we had seen that before,
and it had just gone back
to its previous actions.
This time, it was different.
Why?
Pele knows.
That could be about it.
There's been a series of
volcanic eruptions here,
and I've seen this
has been studied.
What about the chemistry of the
actual lava at different times?
Does that change, or
is that really similar?
It changes over
various timescales.
So for example, the
Hawaiian Islands
formed because there's
something called a hotspot.
Right?
There is this source of
magma in Earth's mantle
that is melting constantly,
and the plate is moving over it
and makes a volcano.
And then that
volcano moves away,
and you get another volcano,
and that's why you have a chain.
As the volcano moves over the
plume, the chemistry changes.
Whether it's on the
outsides, where there's
only a little bit of melt,
over the middle where it's hot
and a lot of melt. So
that's a big scale change.
There are other changes
that, as it goes over there,
it taps different
portions of that plume.
So we actually see some
source differences.
Then, there are differences,
because maybe on its way up
it intersected another
portion of an older flow
or interacted more with--
well, most of that is
pretty subtle stuff.
This eruption was even
weirder, because the first lava
that came out, that
first stuff that came out
of Leilani Estates,
was a type of lava
that we've never
seen in Hawai'i.
It was something
called an andesite,
and an andesite is what happens
when a basalt sits around
for a really long time and
undergoes a process called
crystal fractionation.
And lava in Hawai'i comes
out when it rises up,
and actually, from the
chemical, little subtle chemical
signatures of that,
they discovered
that that was a lava flow.
That other aspects of
that magma had erupted,
I think in 1940s or 1960s--
I can't remember-- and the
rest had just stayed there
in the rift,
fractionated, turned
into something different,
and it got pushed out.
So we can see that.
There are lots and lots of
studies of individual lava
flows and being able to see
distinctions between those, not
the work that I do.
But I know a lot
of that work has
been done in the summit caldera
area to tell its history.
Largely, to tell if
there's one big magma
reservoir, in which case
it would all be mixed,
and it would all at the same.
Or if there are little
pockets, in which case
it would all look different, and
it seems to be more like that.
The hotspot thing
is very interesting.
In Yellowstone,
it's the same thing.
[INAUDIBLE]
So what I wonder about that
is why do you get islands?
Why don't we have one,
giant long mesa volcano?
Right.
There is one place
in the world where
maybe what we have is
one giant mesa volcano.
It's on the seafloor also,
but no, you're right.
You get this [BOOM]
and then that moves,
and you get a second one.
So why doesn't it
erupt continuously?
And probably because, when you
build a volcano, they're huge.
You saw that.
Right?
They're monsters,
and they actually
flex the tectonic
plate underneath them.
And what that does is
it makes some areas--
it puts them in
compression, where
the very plate is
being squeezed,
and lava can't go through there.
Whereas, at the base
of it, it's stretched,
and that's really conducive
to lava pouring up.
And so it keeps
feeding in the bottom,
but it doesn't feed
in right next to it,
because it's squeezing.
But at some point, as
that gets farther away,
it's like, I'm just
going over here,
and it starts a
separate one over here.
So we think it's flexurally
controlled, probably.
Is the plate moving at a
steady rate in the northwest?
Probably.
The plate, there's
only two ways that we
know the speeds of plates.
One is we have to look
at how old things are,
and then we're averaging
over millions of years.
So we can't really tell.
Now, we can use GPS, and that's
a really short time in history.
So there are some
places where we
can see that, not in Hawai'i.
But for example, in
the Tonga arc, what
we see over the
millions of years
is way slower than
what we see right now.
So there's been an
acceleration, but we can't quite
constrain when.
[INTERPOSING VOICES]
This presentation
has been recorded,
as we mentioned
earlier, it's going
to be housed in the
Institutional Repository
that we have here at
Western called CEDAR.
If you'd like more information
about how to access that,
please, see me.
I'm happy to give information.
Let's thank--
[INTERPOSING VOICES]
Thank you all for being here.
Thank you much.
[APPLAUSE]
[MUSIC PLAYING]
