Posted on 12/11/2013 8:05:53 PM PST by LeoWindhorse
A cave on the northwestern coast of Sumatra holds a remarkable record of big tsunamis in the Indian Ocean.
The limestone opening, close to Banda Aceh, retains the sandy deposits washed ashore by huge, earthquake-induced waves over thousands of years.
Scientists are using the site to help determine the frequency of catastrophes like the event of 26 December 2004.
(Excerpt) Read more at bbc.co.uk ...
krakatoa (further East)
I’m guessing that they happen more often than some folks would like to think.
The seafloor around the Hawaiian islands are littered with the remains of massive ancient landslides that produce tsunamis.
They are surprised? This place has earthquakes going off like a percolator.
Living on a beach, I always have tsunamis in the back of my mind. It is my opinion that I am not so subject to a killer tsunami, as I am blocked from the open Pacific by other islands of the Philippines. I am, however, affected by earthquakes, less then 50 km from me. Since the big 8+ quake last month, we now have several small (mag 4 or less) almost every day. Very few are even noticed, and I have seen no surge in waves. The quakes are on Bohol, a large island that I can see from my beach.
If any FReeper is an authority on the subject, I would welcome any opinions.
Pretty cool. Thanks for posting.
MOVE UP THE HILL a bit .....
it is thought that these gigantic landslides might have produced Iminami’s ; super size locally generated wash backs caused by such collapses . The displaced ocean surge back to the shore and has left traces of marine debris to over 1000 ft. in elevation . A space object hit in the ocean would also produce such an iminami .
Aftershocks, and for that matter foreshocks are very common with big earthquakes. I was in a 7.5 in Mexico City (1957?) and as I lay in bed, for weeks after I could feel little rumbles, sometimes several a day. I was in the Virginia earthquake last year. Was sitting on my bed and the wall oposite me started to vibrate and shake for about 15 seconds. At first I thought it might have been a distant bomb/explosion, but when no sound came thought earthquake. At least once in the next several days I felt a faint vibration while sitting, and once saw the surface of a glass of water start to shimmer. Didn’t feel anything then but an aftershock of 2.0 was reported later. Leave a bowl of water out if you want to track the minor ones.
Eight+ is plenty big, but another big one is possible. Google New Madrid Earthquakes, 1811-12 for more info. There were at least 3 8+ earthquakes and many other 7+ over a 4 or 5 month period.
“MOVE UP THE HILL a bit”
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I like living on a beach, as it is still somewhat new for me.
My first 60+ years were hundreds of miles from any sea.
I can gain several hundred feet within 5 to 10 min if I have some advanced warning.
Oh, I did read up on ancient tsunamis. Some traversed the Atlantic all the way from Africa to North and South America.
They have had a huge impact on earth’s population and landscape.
By the way, during my first trip to Asia, 1999, I visited Phuket, Thailand, as well as the resort islands to the north that were later devastated by the Indian Ocean tsunami.
Grab the family and run.
clear a nice wide ,direct path straight up hill . Have an ‘essentials ‘ grab&go pack . Know where you documents are and be sure and grab them . Acquire a pistol and ammo .
“I visited Phuket, Thailand”
in the 2004 event , only certain sections of Phuket were affected , the open ocean sides . Inland sides hardly at all , a few meters up the hills not at all . Lower islands with built up low lying saddles got swept through and devastated the worst . The locals are still seeing the ghosts .
Maybe the PI will be like that in places now too .
“I was in a 7.5 in Mexico City (1957?)”
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Our big quake in October was a 7.2 on October 15.
Even though I see Bohol from my beach, the damage here was not so severe, but broken and leaking water lines still plague the town, and the ancient Catholic church had damage that closed it. Nerves, however, were shaken. My porter and I were shoving a new case of beer under the fridge at the time. We both made a dash to the door and up to the beach road. Aftershocks continue almost daily.
http://www.phivolcs.dost.gov.ph/html/update_SOEPD/EQLatest.html
See those that say Bohol or Tagbilaran. I can see the glow from the lights of that city from my beach. There was a 3.1 just 4 hours ago.
“in the 2004 event , only certain sections of Phuket were affected , the open ocean sides . Inland sides hardly at all”
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Yes, Phuket is a big area...barely an island, as a bridge connects it to the mainland on the north.
The heavy damage was at the seaside resorts along the Indian ocean coast lines.
Tsunamis have little impact on anything other then seashore towns/cities.
in some cases there IS quite a bit of island ‘wrap-around’
I believe it takes deep offshore waters to do that and extensive wrapping tsunamis tend not to occur in the shallow SEA seas so much . Just a theory .
Every tsunami is different .
” The heavy damage was at the seaside resorts along the Indian ocean coast lines.”
and along the Phang Nga province north of Phuket , where the waves went straight in . But not too far . Many were able to escape uphill . However ,if you couldn’t get up that hill you were toast
“in some cases there IS quite a bit of island ‘wrap-around’”
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Yes, the tsunami special that I saw on Natl.Geo ?
emphasized how they can wrap around an island.
That would NOT apply to most all of Cebu island.
How much was Cebu affected by the typhoon ?
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