Major M7.1 Earthquake Strikes Japan; 'Megaquake' Alert Issued

A major magnitude 7.1 earthquake just struck a mere 3 miles offshore of Japan. This generated a tsunami, and caused the ground to shake for 22 seconds. Alongside this, an alert was issued which warned of an increased likelihood of an even larger megathrust earthquake occurring from the Nankai subduction zone. However, I believe this alert to be misleading, which I will explain in today's video.

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Thumbnail Photo Credit: Google Earth, Image Landsat / Copernicus, Data DLEO-Columbia, NSF, NOAA, Data SIO, NOAA, U.S. Navy, NGA, GEBCO. This image was overlaid with text, and overlaid with GeologyHub made graphics (the image border & the GeologyHub logo).

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Thumbnail Photo Credit: Google Earth, Image Landsat / Copernicus, Data SIO, NOAA, U.S. Navy, NGA, GEBCO, Data LDEO-Columbia, NSF, NOAA. This image was overlaid with text, and overlaid with GeologyHub made graphics (the image border & the GeologyHub logo).

A special thanks to the EarthquakeSim YouTube channel for granting me permission to use clips of his footage!
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Google Earth imagery used in this video: ©Google & Data Providers

Various licenses used in sections of this video (not the entire video, this video as a whole does not completely fall under one of these licenses) and/or in this video's thumbnail image (and this list does not include every license used in this video and/or thumbnail image):

Sources/Citations:
[1] U.S. Geological Survey
[2] Japanese Meteorological Agency
[3] Pacific Tsunami Warning Center

0:00 Major Earthquake Strikes
0:24 Megaquake Alert
0:53 Alert, Explained
1:21 Geologic Setting
2:12 Aftershocks
2:40 Damage
3:49 Possible Liquefaction?

[GeologyHub]

I believe that the “mega quake” alert is a bit misleading.

[HomesteadJapan]

I think the megaquake alert serves largely to tell people to make sure their disaster plans and supplies are all up-to-date and stocked properly. I live just outside of where the 2011 tsunami reached (it occurred before I lived in Japan so I was not here for it), so it's definitely on our minds.

[scrappydoo]

Thank you geo hub for the concise update without the usual fear of many other channels

[cheriestolze]

I’m just so grateful for your dedication.

[fwiffo]

If that 2.9% is actually representative, that's a significant increased risk. A typical random week out of the year does not have nearly a 3% chance of an 8+ magnitude earthquake.

[colinswainson]

I live an hour away from the epicenter, we had a violent lightning storm come through just before the quake . I normally don’t mind quakes or lightning storms but both were so violent.

[Aquilae-eobl]

I hope there will be no big earthquake soon and everyone will be safe

[dmdrosselmeyer]

By far the best geology content on YouTube🙏
Been a fan for years, thank you!

[ronaldperez]

Man I was waiting for your video about this earthquake. Yours are the best.

[PsyloSatan]

This is the first place I heard about it. fast work!

[baileyw]

dude i love your videos so much, they're so informational and I always learn so much from them and I love knowing about geological things around the world when they happen because its interesting and important to be aware of your surroundings even if not immediate.

[xwiick]

Thanks for all the hard work on these videos!

[l.mcmanus]

I can continue to count on the channel for clear and concise updates. Thanks for all you great work!

[kaoskronostyche]

Great work. Your summaries are excellent - concise and straight to the point. YOu are one of the best.

[genuinetuffguy]

I’m still wondering about the 5.2 quake that occurred yesterday in Lamont / Grapevine CA that generated some interesting after shocks.

[trailfork]

it's amazing how relatively no damage occured even though this was a magnitude 7, anywhere else a magnitude 7 could cripple a country for months

[sallybaldwin]

I really appreciate how you explained that, about the chances. Nicely done.

[kskssxoxskskss]

Does the "damage model" distinguish between areas where architecture has been reinforced and redesigned for eq safety, compared to places like the New Madrid zone, which totally has nothing -- yet?

[CrackerFL]

It's the liqidfaction that would scare me! Worse than quick sand.

[MelanieCravens]

Your timing is incredible! Yesterday was the "How to reduce earthquake damage before they happen" and today there was an earthquake.