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Deepest earthquake ever detected struck 467 miles beneath Japan
National Geographic ^
| OCTOBER 25, 2021
| MAYA WEI-HAAS
Posted on 10/25/2021 4:12:47 PM PDT by BenLurkin
The first jolt, which struck off the coasts of Japan’s remote Bonin Islands, was recorded at magnitude 7.9 and up to 680 kilometers (423 miles) underground, making it one of the deepest quakes of its size. Then another oddity emerged in the cascade of aftershocks that followed: a tiny temblor that, if confirmed, would be the deepest earthquake ever detected.
The ultradeep quake, described recently in the journal Geology, is estimated to have struck some 751 kilometers (467 miles) beneath the surface in the layer of our planet known as the lower mantle, where scientists have long thought earthquakes unlikely, if not impossible. While there have been hints of lower mantle quakes before, researchers have struggled to pinpoint them within this layer of the Earth.
“This is by far the best evidence for an earthquake in the lower mantle,” says Douglas Wiens, a seismologist specializing in deep quakes at Washington University in St. Louis who wasn’t part of the study team.
Some scientists caution that more research is needed to confirm the quake is real and did indeed strike in the lower mantle. While the boundary sits an average of 660 kilometers (410 miles) underground, it can vary around the globe. Under Japan, the lower mantle is believed to start about 700 kilometers (435 miles) down. The team detected several aftershocks around this depth—but one particular quake sat well beyond.
(Excerpt) Read more at nationalgeographic.com ...
TOPICS: Science
KEYWORDS: boninislands; catastrophism; deepest; douglaswiens; earthquake; earthquakes; fukutokuokanoba; geology; japan; lowermantle; mayaweihaas; mountaso; ogasawaraisland; pumice; pumicestone; quake; quakes; science; tsunami; tsunamis; volcano; volcanoes
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1
posted on
10/25/2021 4:12:47 PM PDT
by
BenLurkin
To: BenLurkin
2
posted on
10/25/2021 4:13:12 PM PDT
by
Samurai_Jack
(This is not about hypocrisy, this is about hierarchy!)
To: BenLurkin
Here, let me save everyone else the effort: Godzilla!
3
posted on
10/25/2021 4:15:58 PM PDT
by
noiseman
(The only thing necessary for the triumph of evil is for good men to do nothing.)
To: BenLurkin
4
posted on
10/25/2021 4:18:38 PM PDT
by
mylife
(Would you rather have Questions without answers? or Answers without questions?)
To: BenLurkin
We're so screwed.
5
posted on
10/25/2021 4:22:38 PM PDT
by
billorites
(freepo ergo sum)
To: noiseman
6
posted on
10/25/2021 4:23:54 PM PDT
by
Fish Speaker
(Quis custodiet ipsos custodes? Oh, and, "Let's Go Brandon!")
To: noiseman
7
posted on
10/25/2021 4:24:54 PM PDT
by
xp38
To: noiseman
8
posted on
10/25/2021 4:25:57 PM PDT
by
mewzilla
(Those aren't masks. They're muzzles. )
To: BenLurkin
9
posted on
10/25/2021 4:30:19 PM PDT
by
conservativeimage
(Spark up a fire. Light up this place. Burn out this darkness and tear down the fear.)
To: BenLurkin
No one has blamed this on fracking in Pennsylvania yet?
10
posted on
10/25/2021 4:36:06 PM PDT
by
Dr. Sivana
("There are only men and women."-- George Gilder, Sexual Suicide, 1973)
To: BenLurkin
Worry, worry, worry.
And how long have we been “detecting” them? For a very short time in Earth’s history.
Worry, worry, worry.
11
posted on
10/25/2021 4:36:34 PM PDT
by
Veto!
(Political Correctness Offends Me)
To: conservativeimage
12
posted on
10/25/2021 4:38:19 PM PDT
by
BenLurkin
(The above is not a statement of fact. It is either opinion, or satire. Or both.)
To: BenLurkin
People have a tendency to imagine the tectonic plates
as being two-dimensional, but they are obviously 3-dimensional
and the exact depth and deep boundaries and pretty much unknown.
13
posted on
10/25/2021 4:39:28 PM PDT
by
Repeal The 17th
(Get out of the matrix and get a real life.)
To: BenLurkin
To: Repeal The 17th
"(tectonic plates) are obviously 3-dimensional and the exact depth and deep boundaries and pretty much unknown"
My question is do they float on the magma? What keeps them from surging relative to the magma? Think of India and how it moved from South Africa to where it is.
15
posted on
10/25/2021 6:07:41 PM PDT
by
Steve Van Doorn
(*in my best Eric Cartman voice* 'I love you, guys')
To: BenLurkin
Yikes.
Dutchsinse says deep earthquakes are usually followed by shower earthquakes a magnitude of order larger.
So a 7.9 deep earthquake will likely result in a shallower 8.9 nearby. If I understand his forecasting methods correctly.
I think he just went live on twitch.
16
posted on
10/25/2021 6:20:24 PM PDT
by
DannyTN
To: DannyTN
shallower earthquakes, not shower earthquakes.
17
posted on
10/25/2021 6:32:11 PM PDT
by
DannyTN
To: BenLurkin
Oh the article is talking about something that happened 6 years ago.
18
posted on
10/25/2021 6:33:16 PM PDT
by
DannyTN
To: Steve Van Doorn
“...do they float on the magma...”
-
That is the way I visualize them.
But huge thick chunks, not thin slivers.
19
posted on
10/25/2021 6:51:28 PM PDT
by
Repeal The 17th
(Get out of the matrix and get a real life.)
To: Steve Van Doorn
I imagine it’s a matter of the planet’s rotation distributing mass equally, to the extent possible.
20
posted on
10/25/2021 8:32:31 PM PDT
by
gundog
(It was a bright cold day in April, and the clocks were striking thirteen. )
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