Return to Transcripts main page
Connect the World
Tsunami Warning Issued For Japan After Magnitude 7.6 Quake. Aired 10-11a ET
Aired December 08, 2025 - 10:00 ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
(COMMERCIAL BREAK)
[10:00:28]
ANNOUNCER: This is CNN breaking news.
ELENI GIOKOS, CNN ANCHOR: Right. Welcome to the second hour of the show from our Middle East programming headquarters. I'm Eleni Giokos. I'm in Abu
Dhabi, where the time is just after 7:00 in the evening and it is just past midnight in Japan, where we are following breaking news there.
Now, a tsunami warning has been issued after a magnitude 7.6 earthquake off the country's east coast. The earthquake struck less than an hour ago,
about 70 kilometers from the Japanese coast, and I want to bring in our Hanako Montgomery, who is in Tokyo. Hanako also felt the reverberations as
far as Tokyo. You can see the map there showing the epicenter of the 7.6 magnitude quake. Give me a rundown Hanako of what we know right now and
what authorities are saying.
HANAKO MONTGOMERY, CNN CORRESPONDENT: We know that a tsunami warning has been issued for parts of northern Japan, so that includes Aomari
prefecture, Hokkaido prefecture, Iwate prefecture, I think you said you had a map right now.
And I just want to point to our viewers, Hokkaido is a northernmost prefecture in Japan, and Aomari and Iwate prefecture are directly below
that, and you can see that they're very close to the epicenter where this earthquake occurred.
Now, Japan is very prone to natural disasters, experiencing earthquakes as a part of daily life here in the country, but of course, this is an
extremely stressful and fearful time for many people in Japan, as this was a very large earthquake, and we are getting tsunami warnings advised now
for parts of northern Japan.
Now, in terms of what the Japanese government will be doing now is to update the public about the tsunami warnings, whether waves will actually
hit parts of the coast, how high these waves will be, and of course, damage. We haven't heard any reports yet of official damage -- official
reports of damage.
But of course, this is a fear, especially given that this earthquake was so large and was felt in many, many places across Japan, including Tokyo,
where I am. Eleni, you mentioned, I was in Tokyo when of course, this earthquake happened. I was just getting ready for bed, but this earthquake,
of course, kept me up, and it was very long for an earthquake, and usually in Japan, that does indicate that it was pretty large, and tremors, of
course, are feared to follow after shocks. Of course, there are a huge concern, also in Japan, given just how much seismic activity the country
does feel, Eleni.
GIOKOS: Yes. I mean, we've also got new video that has just come into CNN. We're going to watch it together. I haven't seen it yet, but let's listen
in.
Wow. And you can see the chandelier there, the lights moving quite dramatically, showing the strength of that earthquake. Hanako, we know that
authorities have issued this tsunami warning. You previously told me the warning is that there will be three meters high. The earthquake happened at
around 11:15, Japan time. It is now just after midnight. How quickly do these tsunamis, and these waves usually hit the coast after the warning or
after the earthquake?
MONTGOMERY: I mean, the tsunami can hit Japan's coast in mere minutes. And of course, the tsunami itself is a bit delayed after that initial
earthquake, which does give residents some time to evacuate to higher ground, as the Japanese government advise people to do. But again, it's
mere minutes.
[10:05:08]
So, for people fleeing the coast, they will feel, of course, that time pressure, that time crunch to get to higher ground, to get to safety.
Now, of course, when people are evacuating, the Japanese government does advise that they get their go bag. Usually, households in Japan have at
least one go bag which is equipped with water, emergency food, heat packs, especially if they live in a cold place like parts of northern Japan, where
this earthquake was very strongly felt.
And of course, they will go to these higher grounds and these evacuation centers so that they can get more information.
But again, the Japanese government does stress that it's important in these minutes to get to higher ground. I mean, these minutes. Can determine
whether an individual lives or not, and it's really, really important to get away from the coast, to get away from this potential tsunami waves,
which can be, of course, deadly, Eleni.
GIOKOS: Yes. All right, Hanako, just hang with me. We are going to go to Derek Van Dam, a meteorologist based in Atlanta for an update on what we're
seeing on the ground there. Derek, what do you have for me?
DEREK VAN DAM, CNN METEOROLOGIST: All right, Eleni, so we're getting some of these initial reports of tsunami, the initial tsunami wave heights in
and around Hokkaido and within the warning areas from The Japan Meteorological Agency.
The good news is that they are below what was forecast so far, roughly about a half a meter. Remember the warning areas, which we'll show you in
just one moment, call for up to three meters of potential tsunami wave height with this latest earthquake.
And so, we're still in the early stages, very fluid and dynamic kind of moment in time right now, but what we do know is that the epicenter of this
magnitude 7.6 earthquake was just offshore from the Aomori prefecture, and due to its proximity, it doesn't take long for tsunami waves to actually
reach the coastline. So that's why this is so critical to get this information out as soon as possible. The warnings issued right away after
that initial earthquake shock, which, by the way, was felt as far inland and as far south as Tokyo.
But reading some of the latest reports from the USGS, there is very strong shaking felts just off the coastline of where the earthquake actually took
place.
So, let's just recap. Give you a little bit of a geographical reference here, right? So, here's Honshu, here's Hokkaido. That's the epicenter of
the 7.6 magnitude earthquake. And what's important here is the depth of the earthquake. Notice it's at 53 kilometers deep, or roughly 33 miles. That's
important information too, because if it was closer to the surface, we would have less absorption, or rather, more wave potential.
But the fact that it is that deep, has the potential to absorb some of the wave energy, that's what we're hoping, right?
So, again, we're in the very initial stages of how this tsunami is actually unfolding in real time.
So, here's the latest warnings from The Japan Meteorological Agency. Remember this shading of red right along the coastline of Hokkaido and into
northern Honshu. This area right near the epicenter, that red X, that's where the earthquake took place. You can see it's just offshore.
Again, this is the area with the most energy, the most seismic energy so there was shaking felt on the ground right around this part of Japan and
into Hokkaido. However, the tsunami, or rather the earthquake, took place under water. So, that's why we have this threat of a tsunami for this
location.
So many of us remember the Fukushima earthquake disaster right with the energy plant just to the south, located right here, looks like it's in the
advisory level group here. That's the shading of yellow along the coastline, according to The Japan Meteorological Agency site that is for
tsunami wave potential up to one meter. But it's the shading of red closer to the epicenter of the 7.6 magnitude earthquake, where we could get those
three-meter-high heights. And so far, they have come in less than what has been predicted.
So, how in the world -- let's just step back and talk about how in the world a tsunami forms in the first place. Remember tectonic plates, the
ring of fire that circumnavigates a good portion of the globe. Well, when these earthquakes happen, we get that shift in the tectonic plates under
water. And what that does is it displaces water, it displaces energy.
So, at the surface level, I'll go back and replay this animation for you. At the surface level, it creates almost a ripple effect in the water, and
that builds as it gets closer and more shallow, water eventually collapsing into a wave. It's not just one wave that's often the misconception of a
tsunami, not one initial wave that comes through. It is a surge of water that continues to move inland depending on the local topography and the
symmetry of the area.
[10:10:05]
So, again, just to recap, Eleni, this is what we have, 7.6 magnitude earthquake. It was just offshore, but under water it was deep. Hopefully
that will kind of absorb some of the earthquake energy, but it is critical right now that we get the information out to viewers in our international
audience that tsunami warnings are in place, advisories are in place in some of these very populated parts of Japan.
GIOKOS: Yes, look Derek, brilliant analysis. And thank you so very much for explaining every technical element. I was going to ask you about the 53
kilometer depth and how significant that is. And just to repeat that, it actually helps mitigate the ocean -- the waves.
But also, what struck me is that we've got to anticipate more than one wave. I mean, how do you -- how do scientists sort of extrapolate what to
expect after a magnitude quake of 7.6, you've got this depth of 53 kilometers, their potential, you know, risks of aftershocks. And then how
long do these tsunamis sort of last for? If you could give us some insight into that.
VAN DAM: Well, here's, here's the reality. This area is no stranger to tsunamis, no stranger to powerful earthquakes, right? It lies right on the
western periphery of this ring of fire that we talk about.
So, seismologists, volcanologists, they understand this area very well. There's so much research that's been done on this part of the Western
Pacific. We know just how deep the ocean water is here. We know how quickly the land underneath the ocean water starts to make its way up and form into
the islands that you see here with Japan.
So, all of that is so critical because it's known as bathymetry. This is -- think about dropping a rock in a pond, and how that ripple effect expands
out in all directions. We can often think about an earthquake occurring underneath the water in a similar fashion, right? We have that ripple
effect where the energy gets, kind of transported in all directions.
Well, just due to the fact geographical nature of where this earthquake took place, the epicenter just offshore. Again, I'm not 100 percent sure on
the pronunciation, but Aomori prefecture, I believe right here in Northern Honshu, this particular area will have the greatest impact from a tsunami
threat just because of its geographical proximity to the epicenter of the earthquake.
So, and I'm going to reiterate this again, Eleni, it's not one wave that comes in with a tsunami. It is a series of waves and a lot of powerful
energy that can get pushed up from the ocean's surface on to shore and onto land where unfortunately, people reside.
GIOKOS: All right. Derek Van Dam, thank you so much for explaining that to us. Good to have you on the show. We appreciate it.
I want to now bring in Ellen Prager, a tsunami expert, and the President of Earth2Ocean. Ellen, great to have you with us on this becoming on this news
of 7.6 magnitude quake.
And importantly, that tsunami warning our Derek Van Dam explaining what we can expect in certain parts of that East Coast. What is your assessment on
the threats and the risk you're seeing right now?
ELLEN PRAGER, TSUNAMI EXPERT: Well, The Japan Meteorological Agency does a great job about putting these warnings out, and you know, as he said, right
now, they're warning for a potential three-meter tsunami in the area that's closest to where the earthquake happened.
And one of the things that we've learned over time, however, is that the bathymetry can actually shift the energy and how it's transmitted from the
tsunami.
So, we used to always say it was like a rip, you know, a pebble and a ripple. But now we know that the bathymetry can actually steer that energy.
So, it's not as easy as just, oh, it's going to be equal all along the area outside of where that earthquake happened, in the seismic waves and the
tsunami travels. But the tsunami models that the agency and scientists are using, they integrate the symmetry and the distance from the earthquake, so
we've gotten pretty good at saying what the size of the tsunami may be and what the timing is.
GIOKOS: Yes, really interesting. I mean, and Derek and also Hanako, our correspondent, was explaining that Japan is very prone to earthquakes. It
is sitting on that juncture with a major tectonic plates.
We also, you know, can never forget what happened in 2011 with Fukushima after that massive earthquake as well. In terms of the readiness of the
Japanese authorities to step in in threats of this kind and you know, preparedness, what can be done after an earthquake that size?
PRAGER: Well, again, as you heard, this is an area where they have big earthquakes, they have volcanic eruptions, they have tsunamis. It's the
Ring of Fire, and it's going to make -- what's really special about the juncture of the plate here is it's called a subduction zone, where,
typically when the plates move, they're moving up and down. And that's the issue here. It's not that they're moving side to side. It's when you have
the displacement of water from the sea floor all the way up to the surface, that's what can trigger a big tsunami, and it's that subduction zone where
the plates move up and down, not necessarily side to side, that is where you have the biggest risk for tsunamis.
[10:15:37]
And the people who live in Japan and the authorities there, they know that, and so they are -- they may be some of the best prepared in the world. They
have early shape warnings for earthquakes, and they now, you know, especially after 2011 with that horrible tsunami, you know, they're much
better prepared.
But again, it's a -- it's a very special circumstance, because you're in a subduction zone, and it's that displacement of water from the sea floor all
the way up to the surface that starts the energy moving. And that's where the danger really lies, out in the open ocean. These appear as short as
very sort of low height waves. They're not very high.
But what happens is, when all of that water starts entering the shoreline and it gets shallower, you can think of it like the bottom starts to feel
the friction of the wave. The bottom of the wave feels the friction, and it starts to get steeper and steeper. And you can either get a surge or big
wave going on to shore.
You don't even see these things out in the open ocean. It's really when they come on shore. And just to be clear, also depends on, do you have
mangroves to have a city? What is it going to hit? That makes a big difference too.
GIOKOS: Yes. I mean, you mentioned the Pacific Ring of Fire, and frankly, just doesn't take you very long to search just how many earthquakes we've
seen just over the past year in that specific area. Some big, some larger.
You know, this tsunami warning is really worrying because, as Derek said, it's just it's not one wave, it's multiple waves. We don't know what energy
that could exert. Give us -- help us understand what you're reading into the tsunami warning that's come off the back of this earthquake.
PRAGER: So, to be clear, typically when you have an earthquake that's about 7.1 magnitude or higher, automatically they start looking for the potential
for a tsunami, just because the magnitude of the quake and that energy.
And so, then, what they're going to do is they're going to look at the history in that area of earthquakes and the kinds of tsunamis they
triggered. They're going to look at the bathymetry and how it changes onto shore. You know, is it very deep, or does it shallow? Very quickly, they're
going to take all of that into account. And that's what, what is comes into this modeling, and where you see they're saying three meters at the in the
closest area.
If you look at the Japan Meteorological Agency site, and it will show you a great map of where they have an advisory, a warning, something like point
two meters. And then the area closest, and it's going to be where the waves travel the fastest, too, is that's where they're saying. It could be about
three meters.
But again, there's a lot that goes into this, and the models are getting better and better at doing that.
GIOKOS: Yes. I mean, the modeling is super important. You know, we've got video of residents in Aomori showing us a chandelier that's just -- as if
someone just exerted major force swinging side to side.
You know, for people living close to the epicenter of the closest parts of Japan to where the earthquake happened, and then people in Tokyo feeling
the tremors. Our correspondent was telling us that she lives on the seventh floor, and she felt her apartment shaking. I mean, this just shows how
tremendously powerful 7.6 magnitude is.
PRAGER: Oh, yes, the 7.6 that's a -- that's a major earthquake. Again, anything above 7.1 and immediately the experts start looking for potential
for tsunami. If it's happened not -- you know, it's not in the water itself. It has to be in the earth under the water, right? That's when they
start looking immediate. 7.6 is a major quake.
GIOKOS: All right, let's talk about potential aftershocks and what the models show us often earthquake of this nature, what are the probabilities
of a an aftershock, multiple aftershocks?
PRAGER: There definitely will be aftershocks, and what happens is they will decrease over time. But you know, you don't -- you can't say absolutely
that the strength of them will decrease after time.
What's happening is the aftershocks occur along the part of the fault that is actually ruptured, and it's what kind of -- at least the size part of it
is interesting is that if you look at the spread of those aftershocks, you'll see the length of fault that has actually broken or ruptured where
that earthquake happened.
[10:20:09]
They won't -- they'll decrease over time, but you could still get some pretty large quakes. So, you know, you don't want to tell anybody, oh, it's
over. Don't worry, they have to prepare for more shaking in the -- and not only hours, but days to come you could have aftershocks.
GIOKOS: All right? Ellen Prager, thank you so much for that update, breaking that down for us. We have more news coming to you from Japan after
a 7.6 magnitude hit parts of the northern parts of the country. We will continue right after this. Stick with CNN.
(COMMERCIAL BREAK)
GIOKOS: Right. It is just past midnight in Japan, and we're following breaking news there. Tsunami warning has been issued after magnitude 7.6
earthquake of the country's east coast. Now, the earthquake struck less than an hour ago, about 70 kilometers from the Japanese coast. I want to
bring in Ellen Prager, tsunami experts and the president of Earth2Ocean.
And Ellen, I'm just looking at some of the updates, specifically from authorities. They're saying that people and residents in parts of Japan
should stay away from the coast. Bringing out that warning, it's pretty explicit in terms of what they need to do. And we also know, and we
discussed this earlier, 30 -- three meters high waves are anticipated. The Meteorological Association also saying that some height increased heights
of the waves have already occurred.
Break down for us what you understand and what you're hearing.
PRAGER: So, from what we're hearing, you know, the three meter is possible, until they actually have a tide gage or water level sensor that measures.
GIOKOS: So, that's maximum Ellen?
PRAGER: Right. Well, no, they don't really say maximum.
GIOKOS: Just to confirm, the three meter is maximum, or is that average?
PRAGER: No, they're saying three meters is possible. It's probably not going to be higher. Most likely it will be lower. But three meters is what
are -- what the models are suggesting.
But the other thing you know, what's really important to mention is it's not necessarily the height of the wave that will make a big difference.
It's also the power of the water. Sometimes these tsunamis come in as surges, and if you saw -- if you've seen video from some of them in some
areas, they don't look like a giant wave, they look like a surge of water, like a really powerful tide. And that the power of water flowing is just as
dangerous as we think of like a big wave, it's really dangerous.
And so, when they have people move away from the coast, it's not only because there could be a relatively large wave, but it's also because of
the power of that water. When the wave breaks, or when it's coming on shore as a surge, it's really strong, and it can knock people over. It can make
cars go floating like a foot of water, and a car will start floating or two feet of water.
[10:25:08]
So, and imagine that moving. So, it's not just that it's a wave. It can be a surge, a powerful surge of energy.
GIOKOS: Ellen, we've actually got a graphic right now from the public broadcaster. Yes, just give me a sec. We are on our screen right now, we're
showing our viewers a graphic that is currently being broadcast on Japan's public broadcaster, the NHK, and this is what residents across Japan are
seeing right now.
And it says, tsunami evacuate, and it's got information about the areas that are affected. It's Hokkaido. It's Aomori we're taking this screen for
I'm not sure if you can see it, but it actually explicitly gives you information on what is going on right now. It says that -- it says reach
time. I'm sure that means that that the tsunami is reaching those areas. What do you make of this information that you're seeing?
PRAGER: Right. You know, I have to read it same way as you it. You know, when it says reach, I suspect that means the tsunami, because remember,
that's closest area to the epicenter of the earthquake, so that's the place it's going to see tsunami waves or surge before anybody else.
So, I imagine you're right. That says that it's reached that area. I'm not sure if it means that it's actually they've measured it three meters, you
know, yes, we don't really know that because the three meters is what they were predicting.
GIOKOS: So, we're also seeing some footage that is also -- yes, we're also seeing some footage that is being broadcast right now, and you can sort of
see still waters there. I mean, the point is, and of course, some vehicles, and this is really interesting, some live footage that we've seen.
People have been told to evacuate and stay away from coastal areas. And remember that they basically had about 45 minutes to do so. This is new
video that we're getting in right now. This is from the Aomori prefecture, one of the areas that is going to be impacted. Oh, it's shaking. Look at
that, Ellen, you can see the shake.
PRAGER: Yes, I can absolutely we can (INAUDIBLE) and they're not very far away.
GIOKOS: Yes, I mean, in terms of aftershocks, I think this is the concern. Is there a possibility here that you could see higher magnitude after what
we've seen, the 7.6?
PRAGER: The only way you would see a higher magnet Earth -- new magnitude earthquake is if this was the 7.6 was a foreshock and not the main shock.
And sadly, there's no way to tell, but it's not likely that that was the case. It's likely that this is the main earthquake, and you'll start to see
earthquakes or aftershocks that are lower magnitude.
The only way it would be higher is if this wasn't the main earthquake, and it was what was called a foreshock that happens before the main earthquake,
and that's, you know, one this big, it's pretty rare that we would see that happen, so I don't think people need to worry about that. We can't rule it
out. But it's pretty unlikely.
GIOKOS: Yes, I mean, it's, it's incredible to see this video. It looks as someone has taken the camera and just shaking it.
So, I'm glad you mentioned about the prediction and the modeling here, and whether they're you know, to what extent have some seismologists have, you
know, resources to be able to explicitly predict the risks and the dangers being on those tectonic plates and whether they can foresee earthquakes.
Have we reached that point yet in sort of technological advancements?
PRAGER: No, we love to say the answer is yes, but it's not. Right now, there is no way to reliably forecast or predict an earthquake. We can say
they're going to be aftershocks here, but we can't predict when and where earthquakes are going to happen.
There are a lot of scientists working and the good thing is now we know where earthquakes are more likely to happen or are more probable. So, we
can build so people who live in those areas are safer, but we still can't say when and where exactly and how big earthquakes are going to be.
But again, we know risk, right? We know where in the world they're more likely to happen, and how people should build to be safer in those areas.
[10:29:53]
GIOKOS: Yes. Just a recap for our viewers just joining us now, a 7.6 magnitude earthquake, hitting northeastern parts of Japan, affecting the
Hokkaido and Aomori prefectures, and also a tsunami warning of three meters has been issued, and people asked to evacuate.
Ellen, I want you to break this down for us. It's 70 kilometers from the coast, 53 kilometers deep. Explain the risks here.
PRAGER: So, remember, so, it's 53 kilometers deep in the earth, but that's under the ocean. And so, because the tectonic plates here --
(CROSSTALK)
GIOKOS: Yes.
PRAGER: Are in what's called the subduction zone, when you have an earthquake happen, typically you have the plates moving vertically. They
are up or down, and when that happens, you are just placing sea water. And so, the sea water moves, and it's important to remember, it's not just
moving on the surface. It's moving from the surface all the way down.
And if you are -- if you are in deep water, that's a lot of energy. And what happens is, it gets translated as a wave out from that area, sometimes
in different directions, sometimes it gets channeled by the bathymetry of the water depths, and then, it goes towards the coast.
When it's in deep water, you are transmitting energy through small waves at the surface, but all the way down to the bottom. As you reach the coast and
it gets shallow, what happens is the wave at the bottom starts to feel its friction from that bottom starts to slow down, but the rest of the wave
keeps going.
And so, while you started with a really long wave, very, probably very low at the surface, it builds up at the shore, and all that energy comes on
shore as a wave or series of waves, or a surge, or a series of surges.
GIOKOS: All right. Ellen Prager, thank you so much for staying the course with me as we unpack this breaking news out of Japan. I appreciate it.
I want to bring in Derek Van Dam, our meteorologist, who is monitoring what we hearing from the Japanese authorities. But importantly, able to tell us
what we can expect.
Derek, we have NHK, which is a public broadcaster in Japan, bringing out and broadcasting this alert. And I want to show you what it looks like.
It's got red signals, saying, tsunami, evacuate. It's got the three-meter warning. Importantly, it's also alerting that there is certain sections
that have seen an increase in wave height.
It says 50 centimeters in some areas, 40 and 30 and 20. Please explain, Derek, what that means. It doesn't seem that significant to have a 20-
centimeter increase in height, but break that down for us and why this is a warning in terms of what is to come.
DEREK VAN DAM, CNN METEOROLOGIST: First of all, I see a couple of different things here. Eleni. What a proficient emergency management warning
communication, right? Getting this information out to their viewers immediately is so crucial because of the short lag time between an
earthquake. This one happening to be underneath the sea and a potential arrival of a tsunami.
The other thing I see here, according to these numbers that you have on top of our screens, 50 centimeters, is the highest observed tsunami. Now, this
is still a very dynamic situation. The potential here for tsunami wave action is not over, but what we are noticing is that it is coming in under
what the projected tsunami height could have been.
So, in the warning areas where the Japan Meteorological Agency has highlighted these areas -- I'll get to that map in just a moment. But
northern portions of Honshu, just right off the Aomori prefecture into the southern coastline of Hokkaido, these are the areas that are closest. They
are nearest to the epicenter of the earthquake, the powerful earthquake.
But when any time this happens, the first thing that I do, the first thing that the team of meteorologists and scientists here at CNN do, and even
seismologists, volcanologists, all the people studying this moment, they look to not only the depth of the earthquake, but also the magnitude.
We know it's powerful, 7.6. You heard the expert just a moment ago say, that's a powerful earthquake. We know that. It is likely to create a
tsunami wave action. But how deep is it? That's so critical? 53 kilometers.
There are three different classifications of this depth of earthquakes.
There is a shallow earthquake. That's basically zero to three kilometers, or 30 kilometers below the surface. There is an intermediate level that's
basically 30 kilometers to 70 kilometers below the surface of the earth, and then, there is a deep earthquake that's over hundred kilometers below
the surface of the earth.
And all of those translate to different types of potential wave action at the surface.
So, this is an intermediately deep earthquake, 53 kilometers allows for the, let's say, the Earth's mantle underneath those tectonic plates that
have shifted and kind of subducted underneath it.
[10:35:07]
It is absorbing some of the energy of this powerful earthquake. So, as it's translated into the surface, the ocean water here, in this particular
instance, it's got a lot of that energy absorbed by the deep nature of the earthquake, or the intermediately deep nature.
So, let's break it down into a better animation so you understand this. So, the expert was talking about how sometimes earthquakes, they slide. The
tectonic plates slide back and forth.
That is not the case with what happened here. With the earthquake underneath the sea bed, it actually created and subducted underneath it.
So, there is a displacement of water.
So, let's pretend the earthquake happens right about there. Now, look at the subduction, you see how that change in the tectonic plates. That sends
a ripple from the sea floor bed, all the way to the top of the ocean surface, and that translates into a wave at the surface. Of course, that
wave grows higher and higher as the wave approaches the more-shallow nature of the water.
Google this: bathymetry. That is the study of the basic kind of ocean geometry, how the coastline is actually laid out. The bathymetry of the
coastline of Japan plays a critical role of where this displaced energy in the form of tsunami wave actually travels.
So, The Japan Meteorological Agency has a lot of previous incidents, previous earthquakes, and tsunamis, that they'll go back in historical
context to, and they say, OK, this earthquake occurred relatively close to this part of Japan, the Aomori prefecture. Right there.
So, we expect the tsunami waves to impact this region first. You saw those numbers flashing on your screen, anywhere on that shading of red up to
three meters. That's what they're calling for. Even southern Hokkaido.
The areas further to the south and further to the north, that's an advisory. So, up to one meter. They know that just because of the
bathymetry, the layout of the underfloor sea bed, how the wave disperses its energy, where the wave will travel first, how deep the earthquake
actually is. All of those into context here to decide how powerful this earthquake or tsunami will be along the coastline.
One thing's for sure. You don't want to be next to the coast after a 7.6 magnitude earthquake underwater occurs. So, getting away from land, that is
the most important thing you can do.
This earthquake was so powerful, we have reports of shaking in Tokyo. We are talking hundreds of kilometers to the south of where the epicenter was.
But the areas where some of the strongest shaking was felt, look at this. Very strong shaking for hundreds of thousands of people, million -- all
right, millions of people feeling strong to moderate shaking. So, this is a very densely populated part, not in comparison to Tokyo, for instance, but
still a lot of people call this area home.
So, even though the earthquake was under the sea floor bed, it was under the ocean, they still felt it on land. So, the U.S. Geological Survey, they
rate the earthquakes almost immediately after the event, and they range it from a green to a yellow to a red ticker.
And right now, they have -- they have issued this as a yellow for the potential of economic losses. And what this means is they are comparing it
to previous earthquakes of similar magnitude, similar location and similar depth. And based on those criteria, they can say with confidence that there
will be some localized damage. Possible impact could be relatively local, but people will feel shaking, and of course, the aftermath and the
aftershocks, this is based on historical data, they are likely to continue for the days to come, if not the weeks. Eleni?
GIOKOS: Yes. I want you to hold that thought, Derek, because we actually have some information. You were saying that the U.S. Geological Survey has
declared it yellow in terms of impact.
The Chief Cabinet Secretary Minoru Kihara made these statements in a press conference earlier and really important. So, while there's a tsunami
warning that has been issued for the Pacific Coast, or Hokkaido, Aomori prefecture and Iwate prefecture, reiterating the three meters high that are
expected, also saying that people need to evacuate and especially move to higher ground.
But then, importantly, and this is something that's vital regarding the Higashidori Nuclear Power Plants and the Onagawa Nuclear Power plant. They
have not received any reports of abnormalities at this time. However, we have received reports that other nuclear facilities are currently being
checked.
So, we must not forget that Japan is reliant on nuclear energy. Has nuclear power plants. We remember what happened in Fukushima in 2011. The Japanese
government very vigilant in terms of making sure that they keep this infrastructure safe, this critical infrastructure safe when you have events
like this.
And then, I have got this question for you, Derek, because you know, the Japanese measure earthquakes differently, and they have a scale from zero
to seven.
[10:40:08]
They have measured this at 6.5 on their scale, which, of course, is danger zone. And we are looking at 7.6 in the way that earthquakes are measured
elsewhere.
Clearly, very vigilant, their predictions and their models very good. They have a lot of experience in understanding what an earthquake of this
magnitude means.
VAN DAM: Yes. So, you know, any way you cut this. Eleni, this was a powerful earthquake. We know, a 7.6, if this was directly on land, if it
was a shallow earthquake on land, we would be talking about significant structural damage, and we can base that off of previous historical
earthquakes of that magnitude.
But this is -- each magnitude, or each earthquake is completely different from each other. This one happens to be just offshore, and the fact that
it's so deep buried within the sea bed, means that not only does it have a layer of mantle or the Earth's crust to absorb energy, it also has the sea
or the ocean directly above it.
So, the threats here are different. So, we won't have the aftershocks that we would have if the -- if the earthquake was directly in land -- inland.
We will still feel shaking. There will still be aftershocks from this, but a lot of that will be concentrated in and around the original epicenter of
this powerful magnitude 7.6 earthquake.
So, there is just so many ways to break this down, and they do, like you said, so rightly so, they have a lot of experience here, coming from the
Japan Meteorological Agency. They are no stranger to earthquakes, tsunamis, the threats that are posed to each individual coastline.
Remember, there is a difference between a southward facing coastline here on Hokkaido and an eastward facing shoreline right off the coast of the
Aomori prefecture, right near where the epicenter occurred under the water.
So, who is going to get the direct impacts first? Well, as it radiates and propagates outward, it's going to be the closest land mass, right? That
would be logically tell you who would see those impacts first.
But as it gets displaced further and further afield, it will impact those coastlines and push the energy around the little peninsulas, the individual
coastlines. And that's why not all tsunamis are created equal.
GIOKOS: Yes.
VAN DAM: They may -- they may call for a three-meter-high wave height, but that doesn't mean that specific location will have three-meter wave coming
in. It means the potential is there, the energy, according to -- you know, previous historical earthquakes of this magnitude is there to create up to
three-meter-high tsunami wave height?
So far, though, we have not experienced that, and so far, we are coming in at least half or under what is projected for this area.
GIOKOS: Yes. All right. Derek, thank you so much for that update. We are going to very short break. We'll bring you more breaking news out of Japan
after that 7.6 magnitude earthquake struck, and, of course, evacuation orders given, a tsunami warning three-meter-high waves. We'll be back right
after this. Stick with CNN.
[10:45:43]
GIOKOS: Right. Welcome back, and the tsunami warning has been issued for parts of Japan's east coast. That's after a magnitude 7.6 earthquake struck
about 70 kilometers out at sea. A CNN team said the tremors were felt in Tokyo. Japanese officials say a tsunami could reach a height of almost
three meters.
I want to bring in another expert on this. We have got Zhigang Peng, who is a geophysics professor at the Georgia Institute of Technology, joining me
now from Atlanta. Zhigang, thank you so much.
We've got this map up showing exactly the epicenter of the 7.6 magnitude quake. Importantly, that three-meter-high tsunami warning has come into
effect. People are currently evacuating. And, you know, we have -- we have spoken a lot about what we were seeing, but I wonder, from your
perspective, what kind of damage is anticipated, how powerful this tsunami could potentially be, what kind of risks do people face that are in the
danger zone?
ZHIGANG PENG, PROFESSOR OF GEOPHYSICS, GEORGIA INSTITUTE OF TECHNOLOGY: Yes. So, as the audience may have already heard that this event is pretty
sizeable. A magnitude 7.6.
And in terms of damage, because it occur, as far we know for right now that the depth is roughly about 50 kilometers or so. And if that depth is
accurate, this hopefully indicating that the tsunami waves would not be as significant as we expected, so, that -- that's probably good news.
But because it's also closer to land, so, I think we would expect to see pretty significant shaking. And as far as I know, so far, the GMA intensity
is six plus. So, that's an indication that's getting very close to the highest intensity level, which is seven.
So, again, it's pretty significant event, as we are seeing right now.
GIOKOS: Yes, I'm glad you mentioned the scale that is used in Japan, because it's from zero to seven, and from what I have seen is that they
have measured this at around 6.5. So, again, it really speaks to the intensity of this.
I was wondering if you could take a look at what NHK is broadcasting right now. And it's pretty phenomenal to see the warning that is on screen giving
a TikTok analysis of the waves that are currently, you know, being seen and measured, telling people to evacuate. This is what's been broadcast, and
basically showing that there is certain areas that has experienced 50- centimeter height waves. Others 20 and 10.
What are you reading into this when you see these alerts?
PENG: Right. So, as you can see that this is happening right now in action. And, of course, one of the reasons is because the Japanese government have
invested a lot of infrastructure.
GIOKOS: Yes.
PENG: So, in that case, we do see those numbers popping up. And those is number, by the way, is sort of consistent of what we would expect to see.
And, you know, of course, when you are issue a tsunami warning, then, typically you would, you know, put the highest possible number, because in
some cases or some area, there may be some sort of amplification effect, right?
So, you normally put a higher number there, but the number we have seen right now, roughly about 10 to about 40 centimeter is, again, what we would
expect for the size of the event and also the depths what they have seen so far.
GIOKOS: Yes. And it's also really fascinating to see the map and showing there is certain areas that are red, there is certain areas that have been
highlighted as yellow, showing the risk areas, and how important is for people to evacuate as quickly as possible.
(CROSSTALK)
PENG: Absolutely.
GIOKOS: That is the warning that people have been given on the ground. Yes.
PENG: Absolutely. And again, I think, that, you know, the reason why we can do this, as I already mentioned, is because the Japanese government has
invested a lot in both on land, as well as offshore cable system. So, in this case, once the event have happened, that they can quickly determine
the size. But in the meantime, they can also measure the tsunami waves as it's propagating.
[10:50:01]
So, in that case they can come up with a pretty good accurate understanding of when and where the waves will hit,
GIOKOS: OK. We have also got Hanako Montgomery, she again, please just hang 10 for me. Hanako, I've got a question for you. What we are seeing coming
through from the chief cabinet secretary in a press conference said, in terms of the nuclear power plants and securing those that critical
infrastructure, that the Higashidori Nuclear Power Plant. is the well, the -- are Onagawa Nuclear Power Plants. They haven't received any reports of
abnormalities, but other nuclear facilities are currently being checked.
What is your understanding on the risks given the magnitude of this quake?
HANAKO MONTGOMERY, CNN INTERNATIONAL CORRESPONDENT: Yes, Eleni. I think there is, of course, very obvious concern that we could see what happened
back in 2011, when a massive earthquake and subsequent tsunami destroyed the Fukushima Daiichi Nuclear Plant. And that was, of course, a very fatal
nuclear disaster, which was also very costly for Japan.
Now, as you mentioned, the chief cabinet secretary has said that they haven't received any reports of abnormalities at those two plants, but they
are checking other nuclear facilities at the moment.
And again, of course, you know this is sort of the run of the mill operations in Japan, when a big disaster like this happens, especially
again after that 2011 triple disaster, Japan does make a point to check its nuclear facilities as well to avoid that sort of nuclear meltdown and that
disaster we saw less than two decades ago.
GIOKOS: All right. Hanako Montgomery, thank you so much.
We still have Zhigang with us. And you know, I was just talking about the nuclear facilities in terms of checking every facility. Two nuclear
facilities have not reported any abnormalities, and we will never forget what happened at Fukushima in 2011, given that Japan relies so heavily on
nuclear power, and you've got nuclear power plants in a place that is so earthquake prone, with major tectonic plates and movement there.
what is your understanding on the monitoring of these facilities and ensuring they are safe, even when you have a magnitude quake of this kind?
PENG: Right. So, as you already noticed, that there are quite a few nuclear power plant in Japan, and of course, many of them are located near
shoreline, because that's what normally those nuclear plants are placed on.
GIOKOS: Yes.
PENG: From what I can see so far, that, you know, the magnitude of this event 7.6 is, I assume that within the design range of those nuclear power
plant -- power plant.
You know, of course, having said that, there is always a very small, non- zero, but very low probability that some larger event could happen. And this is actually exactly what happens in 2011. Right? Before the main
event, which is 9.1, there was a magnitude 7.3 earthquake occurred three days earlier. So, this is not to say that something big is going to happen,
but there is a very small, but non zero chance that there may be a larger event following in the next seven days, but the odds is very small.
I assume the Japanese government is probably monitoring this closely to understand whether or not there are --
(CROSSTALK)
GIOKOS: Yes.
PENG: There is an increased risk after the 7.6 event.
GIOKOS: Yes. I'm so glad you mentioned this, whether you -- we know, one of the probabilities about it being a pre shock or the actual earthquake, and
whether we'll see an aftershock, in terms of modeling on the scenarios that could play out, what are you anticipating?
PENG: Great question. So, like I said, typically, if you look at either Japan or globally, there is always what they call is five to 10 percent --
five to 10 percent chance. Or one out of 10 or one of 20, chance that something larger will happen in the next seven days.
So, the odds are very small, but it's getting non zero. But more likely, we are going to see a lot of aftershocks, and which is already being reported.
So, again, typically, we know that, you know, there will be aftershocks up to about 9.6 or so, and of course, the rate will decay. So, that's the kind
of the normal behavior. But of course, as you know, the Earth doesn't always behave like what we expect to see. And in a very small chance that
there may be something larger is going to happen, but most likely, I would say 90 to 90 percent chance that --
(CROSSTALK)
GIOKOS: Yes.
PENG: To 95 percent chance there will be mostly small aftershock follow the main event.
GIOKOS: Yes, and I mean, absolutely scary for people living close to the epicenter and close to the danger zones. And importantly, people, and even
our colleague Hanako Montgomery reported that as far as Tokyo, she felt her apartment shake and move, and it lasted for 30 seconds.
[10:55:08]
You know, in terms of understanding what it must feel like to live in such an earthquake prone zone and country and area with these types of warnings.
What do we understand on the support on the ground that is given? Because it seems the Japanese government, you know, steps up very quickly when you
see these dramatic events.
PENG: Right? So, if you are thinking about in terms of the building code. And I think that we think Japan's probably have the high -- one of the
highest building code in terms of shaking, because of the size of events that I would expect, probably maybe, like majority of the, you know, the
island of Japan, will feel the event. And obviously, if you are further away from the epicenter, you feel the shaking longer, but the amplitude, or
the shaking is smaller. And I assume that, in this case, the GMA's early warning system would work. So that in this case, if you are stay away from
the epicenter, you hopefully would also receive a warning message to tell you that maybe in a few second or tens of second, the assessment we're able
to hit that certain region.
(CROSSTALK)
GIOKOS: Yes.
So, that information is also very useful for people to take precaution if needed.
GIOKOS: Yes.
Zhigang, thank you so much. Thank you so much for guiding me through what we are seeing, and of course, we are thinking of the people that are in the
danger zone right now in Japan, north eastern parts of the country.
We continue our breaking coverage of the 7.6 magnitude earthquake that has struck Japan as a tsunami is expected to hit certain parts of the country.
From me, Eleni Giokos, thanks for joining us. "ONE WORLD" is coming up next with continued breaking coverage. Stay with CNN.
(COMMERCIAL BREAK)
END
