A Slow Emergency and a Sudden Slump

UC Berkeley | May 7, 2018 | Berkeley Seismology Lab

[seastay]

This type of motion is not new, it actually has a name. It is called the Hilina Slump. During the last strong quake in Hawaii, a magnitude 7.2 event on November 29th 1975, this slump slid toward the ocean by about 11 feet. Another temblor, the 7.9 magnitude Hawaii quake of 1868 caused the slump to move as well, resulting in a tsunami with a maximum wave height of about 60 feet.

With all respect for the people who are being affected by the current eruption, the way Kilauea lava comes to the surface is rather tame. It crawls slowly along the ground and one can easily outpace it at a leisurely walk. In this sense, the ongoing eruption is a slowly developing emergency, which gives people enough time to react and take shelter.

A complete failure of the cliff at the southern side of Hawaii along the extensional Hilina Fault system, however, would generate a huge, sudden disaster. It is estimated that about 10 percent of the island’s total volume could be affected by the collapse. The huge slide could generate a magnitude 9 quake, which is comparable to the largest earthquakes ever measured. It would also generate a megatsunami with an estimated wave height of more than 1000 feet throughout the islands. Geologic records show that about 110,000 years ago, long before any of the adventurous Polynesian seafarers had reached the island chain, Hawaii was rocked by such a slump and engulfed in the resulting huge tsunami. However, a repeat of such a rare catastrophic event is highly unlikely and it may take many millennia for it to occur.(hra155)

[seastay]

Data shows the edge of the big Island is slipping off into the ocean in a process called the Hilina Slump. While the eruption of lava from Kilauea is happening along fissures , it is evident this is all occuring along a straight fault line bisecting the island’s edge as predicted in an analysis from 2012 ( see video) which means a huge mass could break off and fall into the ocean generating a local 1000 foot tsunami reaching the mainland west US cost of up to 100 feet. The news hasn't seem to pick up on this potential threat, but officials must know an avalanche involving 10 percent of the island might be in play.

https://youtu.be/VvMUJKFjAiA

[BunnySlippers]

Apparently the Hawaiian Islands have had 70 of these slumps in the past. But it is a big event:

https://www.youtube.com/watch?v=VvMUJKFjAiA

[LeoWindhorse]

I dread this..... Prepared to flee UPHILL at any felt major quake , on a moments notice . ALL coastal life will be swept away , up to somehere near 1000 ft.

[Reno89519]

Is this written be the same people that say Yellowstone is about to erupt and destroy most of the US?

[Right Wing Assault]

Here’s a link to the article:

http://seismo.berkeley.edu/blog/2018/05/07/a-slow-emergency-and-a-sudden-slump.html

[Robert A Cook PE]

I am amazed. They did not link the potential landslide (along the fault) to global warming.

[moovova]

Holy cow!

[robroys woman]

Is this written be the same people that say Yellowstone is about to erupt and destroy most of the US?

---

Well, that too. We’re all gonna die, some sooner than others. I think I’ll have another cigarette. ;)

[Ozark Tom]

And let’s not neglect mentioning the Cascadia Subduction Fault destined to deliver a possible 9.0 Earthquake and Tsunami twofer to the left coast. Urban renewal double-whammy in no more time than getting a Starbucks fix with pie on the side.

[SunkenCiv]

that is odd. :^)

[gleeaikin]

Some years ago, CSI Miami had an episode where they had a 30 foot tsunami event because of a slump into the sea from either the Azores or the Canaries. There have been much bigger slumps from that area in the past.

[Robert A Cook PE]

Yes, that Azores slump is another disaster. To be blamed on CAGW also. Sea level rise ya know. Of 1 inch per decade.

[SunkenCiv]

There’s some topics about the Canary Islands crack, hmm...

http://www.freerepublic.com/tag/lapalma/index