Big Sumatra Quake: Wave hits Sri Lanka, India,

[marcus]

this BBC article has a map
http://news.bbc.co.uk/2/hi/asia-pacific/4125481.stm#map

people who regularly watch broadcast TV will have already seen this
but those who don't (like myself) may not have

many thousands of lives were lost in the Tsunami which spread out from the point in Indonesia where the quake occurred
the quake was said to be the worst in 40 years
(I haven't had time to compare several sources for confirmation)

 

[marcus]

here are some technical specs on the quake from the USGS

http://earthquake.usgs.gov/eqinthenews/2004/usslav/

the quake was 8.9

I read somewhere that at the quake the seafloor (temporarily?) shifted up or down by several (I won't say how many) meters----this sounds like it needs confirmation, does anyone have something more exact about this

 

[tumor]

I heard that whole Earth has stopped moving or something like that ,Holy Cow! maybe that is it for us humans.Mother Earth is trying to shake out this vermin/pest out of itself.

 

[marcus]

I heard that whole Earth has stopped moving or something like that ,Holy Cow! maybe that is it for us humans.Mother Earth is trying to shake out this vermin/pest out of itself.

dont worry we can just put ashes on ourself and beat ourselves with
a few tree branches and everything will be all right
this has been tried in Europe some time ago and worked fine
I saw it in the Ingmar Bergman movie called "Seventh Seal"

 

[PerennialII]

!

Wonder how fast can those things travel ... isn't there like a possibility to give a warning or something after the quake is registered, the word tsunami alert rings some bells ? Was just wondering since it did happen quite far off from India and Sri Lanka, which appear to have suffered the most.

 

[Wave's_Hand_Particle]

this BBC article has a map
http://news.bbc.co.uk/2/hi/asia-pacific/4125481.stm#map

people who regularly watch broadcast TV will have already seen this
but those who don't (like myself) may not have

many thousands of lives were lost in the Tsunami which spread out from the point in Indonesia where the quake occurred
the quake was said to be the worst in 40 years
(I haven't had time to compare several sources for confirmation)

There is a possibility that the earthquake of : http://sify.com/news/fullstory.php?id=13635761

May have been a 'trigger' for the one in Indonesia.

 

[Marijn]

!

Wonder how fast can those things travel ... isn't there like a possibility to give a warning or something after the quake is registered, the word tsunami alert rings some bells ? Was just wondering since it did happen quite far off from India and Sri Lanka, which appear to have suffered the most.

Considering the depth of the sea in the are, i'd say around 700/900 Km/h
The deeper the sea, the higher the velocity.
A tsunami only becomes destructive once the seafloor starts rising.
Then the water column and velocity (due to friction with the rising seafloor) decrease.
The energy "stored" in the 6Km column of water can't just disapear.
In other words, it has to go somewhere, in case of a tsunami it means the watercolumn elevates abouve the normal sealevel.
By how much is dependable on how steeply the seafloor rises and the original depth and velocity.

In Sri Lanka the sea floor rises very steeply from around 5Km deep to the surface, in other words the actual wave hitting the beach is enormous.
From the coastline land inwards, the land is rather flat, in some parts even diving below the normal sealevel.
Because of this the wave can penetrate the land for a great distance before it has lost enough of it energy to no longer be destructive.
I believe in Sri Lanka the wave penetrated the land for over a Km before finally loosing its power.

After the wave has lost its power, the water will start running back to sea, the current will drag anything that is loose or not bolted (very securely) back into the sea.
Ant human trapped in this current (and miracilously is still alive) will most likely be crushed to death by debry.

In short, a Tsunami is a *****.


About the warning part.
In Thailand the communications are good enough to be able to warn a lot of ppl with an 45min warning.
This is not the case for small islands and most of India/Shri Lanka, this is the reason most of those ppl didn't know what hit them.
Ironically, a lot of ppl actually came to the shore to whatch a mysterious drop in sealevel, a prelude to a Tsunami.
To bad they didn't know what the were looking at. :grumpy:

 

[Marijn]

There is a possibility that the earthquake of : http://sify.com/news/fullstory.php?id=13635761

May have been a 'trigger' for the one in Indonesia.

Who knows.
Could have been because of that quake, or just because this one was due.
Good chance you'll never know.

 

[Astronuc]

Regarding earthquake-tsunami warning system around Indian Ocean

http://story.news.yahoo.com/news?tmpl=story&cid=514&e=2&u=/ap/20041227/ap_on_re_as/quake_warning_system

"BANGKOK, Thailand (AP) -- The extraordinary loss of life from Sunday's earthquake and tsunami waves has prompted Asian governments to consider developing a more comprehensive and effective warning system so that more lives can be saved in future natural disasters.

Scientists nearest the quake's epicenter knew shockwaves could create tidal surges that would threaten coastal regions and shipping, but said Monday they had no way of measuring the size of the danger because a warning network like the one used in the Pacific is not installed in countries lying on the Indian Ocean.

The technology could have saved countless lives in this week's disaster by giving residents in coastal areas -- especially in Sri Lanka and India, the hardest-hit nations hundreds of miles from the quake site -- time to flee to higher ground.

Officials in Thailand issued the only warnings of Sunday's impending carnage -- but the radio broadcasts beamed to tourist resorts in the country's south vastly underestimated the threat and a Web site caution was posted three hours after the first waves hit."

 

[Orion1]

Sensitive Seismicity...

unleashing 20-foot tidal waves that ravaged coasts across thousands of miles

9.0-magnitude earthquake, strongest in 40 years.

The earthquake hit at 6:58 a.m. and the tsunami came as much as two-and-a-half hours later, without warning.

SAN JOSE, Calif. -- For decades, scientists say, tiny islands off the west coast of Sumatra have been sinking -- an ominous sign that strain was building toward Sunday's great earthquake, which set off tidal waves that killed thousands of people.

The resulting waves, or tsunamis, would have been only a foot or so tall as they raced across the ocean at 500 to 600 mph.

But when they hit shallower water near shore, they piled up into walls of water up to 30 feet high, depending on the shape of the coastline and the contours of the ocean bottom.

As the first one receded, exposing the ocean bottom, people would have been tempted to go gather up any fish left behind, only to be trapped by a second wave as powerful as the first, arriving 10 minutes to an hour later. Four or five tsunami waves may hit in succession, traveling thousands of miles to menace distant shores.

Sunday's 9.0-magnitude earthquake occurred in an area about 125 miles off the west coast of Sumatra that is marked by a deep trench.

Based on clues found among the area's coral reefs and along its beaches, scientists know this is the fourth giant earthquake to strike the same fault zone, known as the Sumatran subduction zone, since 1797.

Here one giant plate of the Earth's crust is diving beneath another, pushing the ocean bottom underneath Sumatra at a rate of about two inches per year. The plates can become stuck, accumulate strain for decades or centuries and then suddenly spring loose in an earthquake.

Sumatra, much of the subduction zone had been locked and building strain since the last giant earthquake in the 19th century, said Kerry Sieh, a paleoseismologist at the California Institute of Technology in Pasadena who has been working in the region.

During Sunday's quake, he said, it's likely that the two plates suddenly slipped past each other by about 40 feet along the fault zone. This released the downward pressure on the ocean bottom, allowing it -- and the little islands it carries -- to spring up about 6 feet. At the same time, the west coast of Sumatra would have dropped by about a yard, enough to flood low-lying villages during high tide.

The center gets advance warning of tsunamis from six instruments in the Pacific Ocean operated by the National Weather Service. Located at depths of 10,000 feet or more, they look for small increases in the weight of the overlying water caused by the bulge of a passing tsunami. The information is transmitted to buoys on the surface and then to the warning center, which notifies state authorities.

Richter Scale:
$$R = \log \frac{I_R}{I_0}$$

Richter-Orion Scale:
$$10^R = \frac{I_R}{I_0}$$
$$I_0 = 2.390*10^{-7} \; Megatons \; (Mt)$$ - Richter-Orion zero-level Constant
$$I_R = I_0 10^{R}$$ - Richter-Orion Scale Magnitude

Magnitude 9.0 Richter-Orion Magnitude:
$$I_{9.0} = I_0 10^{9.0} = 239.005 \; Megatons \; (Mt)$$

$$\boxed{I_{9.0} = 239.005 \; Megatons \; (Mt)}$$

The Richter Scale is a measurement of a seismic magnitude, however, the Richter-Orion Scale is a measurement of a seismic events...destructibility.

The largest nuclear weapon ever detonated was the Tsar Bomba, which had a yield of 50 megatons of TNT (210 PJ). The most powerful nuclear weapon ever produced was a version of the Tsar Bomba that would have yielded some 100 megatons of TNT. Typical H-bombs today have a yield of around 1 megaton of TNT.

The impact of a roughly kilometre-wide meteorite with the Earth can yield upward of 10 million megatons of TNT. Such impacts have been hypothesized to be the cause of prehistoric extinction events.

Based upon the Richter-Orion equation, what is the R (Richter) value for 1 kiloton?

Based upon the Richter-Orion equation, what is the R (Richter) value for 1 Megaton?

Based upon the Richter-Orion equation, what is the R (Richter) value for 10 Mega Megatons?

Seismograph record:
http://neic.usgs.gov/neis/bulletin/neic_slav_r.html

Reference:
http://en.wikipedia.org/wiki/Kiloton
http://www.harktheherald.com/modules.php?op=modload&name=News&file=article&sid=43753&mode=thread&order=0&thold=0

 

[Ronhrin]

I guess most people don't realize the scale of this incident, so far there are 40 thousand death found officialy, but there are a lot more people missing, unofficialy the number already crosses the boundary of 100 thousand death, we are talking of more than the double of death of hiroshima/nagasaky bombs, this is one of the biggest incidents in history

 

[russ_watters]

More on warning systems: there are several in the pacific and they work rather well: http://wcatwc.gov/

Unfortunately, these countries are not developed enough to have them - and even though the site I linked above put out a warning, these countries don't have the necessary infrastructure to promulgate it. It really is sad - with 1-3 hours notice, there is no reason why those beaches shouldn't have been utterly deserted.

 

[tumor]

How did sea mammals and other critters reacted to early signs of incoming wave?

 

[hitssquad]

there are 40 thousand death found officialy, but there are a lot more people missing, unofficialy the number already crosses the boundary of 100 thousand death

With all of the deaths on the micro islands that apparently suffered complete genocide and have not officially been counted yet, plus all of the malaria, cholera, exposure and starvation that with claim more lives in the next month, it seems to me that the death toll will top one million by February 2005.
http://www.voanews.com/english/2004-12-28-voa50.cfm

• And, Patrick Nicholson of the Catholic Agency for Overseas Development suspects the worst for inhabitants of islands off the tip of Sumatra, close to the epicenter of Sunday's powerful quake.
  
  "Government reports say the population there, 76,000 ... planes, spotter planes went to the area and they saw no people whatsoever on the islands, badly destroyed," he said.

 

[errorist]

You know, a nuke placed in the right location on a fault line could be the primer for such an event!

 

[tumor]

There are few US and Russian nuclear subs with nukes lying and rusting on the seafloor, who knows maybe one just blew up.

 

[russ_watters]

There are few US and Russian nuclear subs with nukes lying and rusting on the seafloor, who knows maybe one just blew up.

We do know the quake was not caused by that. Explosions have a distinct seismic signature.

 

[Astronuc]

The USGS website puts the event at about 30 km (18.6 miles) "set by location program", which apparently is close to the default value for earthquakes under the ocean floor - so this is not a thermonuclear warhead detonating on the seafloor, which would have been more radially symmetric anyway. The tsunamis went predominantly E-W.

The earthquake was much bigger than the major nuclear warheads.

 

[Gokul43201]

Wiki has a nice page on this.

The 2004 Indian Ocean Earthquake was an undersea megathrust earthquake of moment magnitude 9.0 that struck the Indian Ocean off the western coast of northern Sumatra, Indonesia on December 26, 2004 at 00:58:53 UTC (07:58:53 local time in Jakarta and Bangkok). It was the largest earthquake on Earth since the 9.2-magnitude Good Friday Earthquake which struck Alaska on March 27, 1964, and the fourth largest since 1900 (tied with a 1952 earthquake of 9.0 magnitude in Kamchatka). Tens of thousands were killed by tsunamis of heights of up to 15 m, which flooded coastlines between 15 minutes and 10 hours after the quake, causing one of the deadliest natural disasters in modern history..

The multiple tsunamis struck and ravaged coastal regions all over the Indian Ocean, devastating parts of Indonesia, Sri Lanka, India, Thailand and other countries. Deadly tsunamis struck as far away as Somalia and several other countries on the east coast of Africa, 4,500 km (2,800 mi) or more west of the epicenter. Global ripple effects were so widespread that wave fluctuations passed into the Pacific Ocean and caused tidal disturbances in North and South America.

The hypocenter was at 3.298°N, 95.779°E, some 160 km (100 mi) west of Sumatra, at a depth of 30 km (18.6 mi) below mean sea level, within the "Ring of Fire" zone of frequent earthquakes. The quake itself (apart from the tsunamis) was felt as far away as Bangladesh, India, Malaysia, Myanmar, Singapore, Thailand and the Maldives.

The earthquake was unusually large in geographical extent. An estimated 1,200 km (740 mi) of faultline slipped 15 m (50 ft) along the subduction zone where the India Plate dives under the Burma Plate. The seabed is estimated to have risen 10m vertically, creating shock waves in the Indian Ocean that traveled at up to 800 km/h (500 mi/h), forming tsunamis when they reached land.

The moment of inertia of Earth is believed to have decreased a bit due to the earthquake. Because angular momentum is conserved, this would result in an increase of the angular velocity of Earth's rotation. In other words, the earthquake may have shortened the length of a day by as much as 3 µs. However, due to tidal effects of the Moon, the Earth's rotation slows by 15 µs per year, so any rotational speedup due to the earthquake will be quickly negated. The massive release of energy and shift in mass may have also caused the Earth to minutely "wobble" on its axis.

 

[Orion1]

Geophysics Geovortexes...



Based upon these photos, I notice that tsunamis also appear to produce large scale whirlpools and vortexes and gigantic swirl pattern waves, from both the negative and positive tsunami amplitudes, which would seem to require further catagorization.

The determination of anything caught in such massive vortexes, is probably fateful.

The most powerful Earthquake on record was 9.5:
$$I_{9.5} = 755.784 \; Megatons \; (Mt)$$

The 11 largest global magnitude seismic pattern occurs in the Pacific Ocean along the 'ring of fire' crustal fracture:
http://neic.usgs.gov/neis/eqlists/10maps_world.html

Accordign to the statistical Law of Averages for the 11 largest recorded global magnitude seismic events, to record such events occur with a frequency of 8.9 years and have an average magnitude of 8.855.
$$I_{8.855} = 171.158 \; Megatons \; (Mt) \; every \; 8.9 \; years$$

Based on the statistical Law of Averages for the 11 largest recorded global magnitude seismic events, the next expected large magnitude quake is expected to occur around 2013 with a magnitude around 8.9 around the Pacific 'ring of fire'.

Excellent satellite photos of the tsunami event!:
http://www.digitalglobe.com/images/tsunami/srilanka_kalutara_beforeflood_jan1_2004_dg.jpg
http://www.digitalglobe.com/images/tsunami/srilanka_kalutara_beach2_dec26_2004_dg.jpg
http://www.digitalglobe.com/images/tsunami/srilanka_kalutara_flood_dec26_2004_dg.jpg
http://www.digitalglobe.com/tsunami_gallery.html
http://www.digitalglobe.com/sample_imagery.shtml

 

[Gokul43201]

There are few US and Russian nuclear subs with nukes lying and rusting on the seafloor, who knows maybe one just blew up.

More conspiracy theories ? You're not being serious, are you ?

 

[tumor]

The USGS website puts the event at about 30 km (18.6 miles) "set by location program", which apparently is close to the default value for earthquakes under the ocean floor - so this is not a thermonuclear warhead detonating on the seafloor, which would have been more radially symmetric anyway. The tsunamis went predominantly E-W.

The earthquake was much bigger than the major nuclear warheads.

Okay,okay, could then not America send few nuclear bombs against the tsunami waves and make them smaller or something? :uhh:

PS. if I still remember from physics lessons, ther is some stuff about destructive interference of waves right?

 

[Gokul43201]

Okay,okay, could then not America send few nuclear bombs against the tsunami waves and make them smaller or something? :uhh:

PS. if I still remember from physics lessons, ther is some stuff about destructive interference of waves right?

Holy cow, you are serious !

Please tell me you're kidding.

 

[tumor]

Well...it is late, I'm going to think about it more tomorrow.see you

 

[Jeebus]

Does that mean that our net gain of day microseconds will increase by 12? I know that our calenders are supposed to be super accurate considering the time they were made, but would this cause a need to adjust the calenders earlier than expected a thousand or so years down the road?

The wobbling of the earth, is it something akin to a warped record spinning on a record player or more like when a cat smacks a tennis ball with its paw?

 

[russ_watters]

The wobbling of the earth, is it something akin to a warped record spinning on a record player or more like when a cat smacks a tennis ball with its paw?

The best analogy I've heard is "ringing like a bell."

 

[Astronuc]

Sending a

few nuclear bombs against the tsunami waves

is not practical - 1. fallout contamination and 2. the size (breadth) and scope of the tsunamis would preclude effective use.

Remember that a particular earthquake, and therefore its effects, cannot be predicted.

The most effective response is continuous monitoring (we know where earthquakes are likely to occur), detection, communication/alert, and evacuation.

People need to realize that living along an ocean/sea coast line poses risks from natural events like storms (e.g. hurricanes in SE US or typhoons in Western Pacific) and earthquakes/tsunamis. In delta areas, such as the Ganges delta, Bangladesh periodically experiences catastrophic flooding.

Also living in a mountainous area exposes one to earthquakes, avalanches and floods, and living in a forested area exposes one to forest fires.

Best to pay attention to Nature.

 

[Orion1]

Terran Tsunamis...

More than 36,000 people were killed by tsunamis following the explosion of the volcano Krakatau in the Sunda Strait near Java on Aug. 27, 1883. Many estimates of the number killed in that disaster were even higher.

The toll from Sunday's tsunamis has now topped 60,000 deaths in 11 nations.

Following the 1883 eruption, waves estimated as high as 90 feet slammed ashore on nearby islands, wiping out coastal communities in what is now Indonesia. They had been the deadliest tsunamis of modern times until now.

The earliest description of a tsunami-type wave comes from 479 B.C. in the northern part of the Aegean Sea. Similar waves have been reported worldwide, though they are more common in the Pacific, with its earthquake-prone perimeter.

Many historians believe the explosive eruption of Santorini in the Aegean Sea in 1500 B.C. caused a tsunami that brought widespread devastation to the eastern Mediterranean and Crete.

Thousands of coastal residents in Spain, Portugal and North Africa were killed by waves spawned by an earthquake at Lisbon, Portugal, in 1755.

Over the centuries, Japan has been the land most plagued by tsunamis, with at least 66,000 deaths recorded there since A.D. 684.

On April 1, 1946, a Pacific-wide tsunami was generated by a magnitude 7.8 earthquake near Unimak Island in Alaska's Aleutian Island chain.

A huge wave destroyed the U.S. Coast Guard's Scotch Cap lighthouse on Unimak, killing all five of its occupants. The lighthouse was a steel-reinforced concrete structure standing about 90 feet above sea level.

That tsunami reached the Hawaiian Islands about five hours later, obliterating Hilo's waterfront and killing 159 people.

Altogether, 165 people died, including children attending school at Hawaii's Laupahoehoe Point, where waves reaching up to 25 feet struck.

Reference:
http://www.harktheherald.com/modules.php?op=modload&name=News&file=article&sid=44010&mode=thread&order=0&thold=0

 

[Gokul43201]

Sending a is not practical - 1. fallout contamination and 2. the size (breadth) and scope of the tsunamis would preclude effective use.

Not to mention that you want to exactly match the waveform (which is not a spherical wave because the source is some weirdly shaped faultline), the position, and get the timing right to within a small fraction of the time period...all this in addition to knowing in advance the location, shape and strength of the tremor.

Oh yes, and try setting off a few dozen nukes in China's backyard without starting WWIII.

Besides all this, you can not start off with a rarefaction. Your wavefront is always going to be a compression, so there's nothing you can do about that.

I can't believe I'm actually writing this up. :grumpy: Even sci-fi cartoon shows wouldn't come up with ideas like that one.

 

[errorist]

I think you guys got it all wrong. I am not saying a bunch of nukes could be used. I am saying just one could be used to trigger a much larger event if it were placed in the right location like on a weak spot on a fault line!

 

[Gokul43201]

Does that mean that our net gain of day microseconds will increase by 12? I know that our calenders are supposed to be super accurate considering the time they were made, but would this cause a need to adjust the calenders earlier than expected a thousand or so years down the road?

The calendars get adjusted much more often than you think.

In 1752, when we switched to the Gregorian calendar, they had to take off 11 days to fix the calendar !

In the 60s, the new calendar based on Ephemeris Time was established, and with a few small changes things were fixed.

Then in '67 the new definition of the second was implemented, and about a decade later, we switched (yet again) to a new time scale - Terrestrial Time. Each switch requied a recalibration and resetting of time.

So really, making a one second adjustment, several millenia from now should not be a worry.

 

[marley.wannabee]

this BBC article has a map
http://news.bbc.co.uk/2/hi/asia-pacific/4125481.stm#map

people who regularly watch broadcast TV will have already seen this
but those who don't (like myself) may not have

many thousands of lives were lost in the Tsunami which spread out from the point in Indonesia where the quake occurred
the quake was said to be the worst in 40 years
(I haven't had time to compare several sources for confirmation)

Marcus, thanks for starting this off right and bringing it along. This is by far the best thread on the net(i only speak english) pertaining to this.

 

[Orion1]

Titanic Tsunamis...

Aug. 16, 1976
A tsunami generated by a quake on Mindano in the Philippines killed between 5,000 and 8,000 people in the Moro Gulf region.

March 28, 1964
A magnitude 8.4 quake in Alaska generated tsunamis that caused damage in southeastern Alaska, in Vancouver Island, British Columbia, and in the states of Washington, California and Hawaii. More than 120 died.

May 22, 1960
The largest earthquake - magnitude 8.6 - of the 20th century occurred off the coast of south central Chile. It generated a Pacific-wide tsunami, which was destructive locally in Chile and throughout the Pacific Ocean. The tsunami killed an estimated 2,300 people in Chile.

Jan. 31, 1906
A strong tsunami struck the coast of Ecuador and Colombia, submerging half of Tumaco, Colombia, and washing away half of a nearby island. The death toll has been estimated at between 500 and 1,500.

Aug. 13, 1868
A massive wave struck Chile, carrying ships as far as three miles inland at Arica. Deaths totaled 25,000 or more.

April 2, 1868
A locally generated tsunami swept over the tops of palm trees and claimed 81 lives in Hawaii.

On April 1, 1946, a 7.3 earthquake in the Aleutian Islands generated a tsunami which struck the Hawaiian Islands. The tsunami claimed the lives of 159 people in (what is now known as) the state of Hawai'i (122 from the Big Island) and caused $26 million in damages.

On November 5, 1952, an 8.2 earthquake occurred off the Southeastern coast of the Kamchatka Peninsula of the Russian Far East. Tsunami waves were generated and spread across the North Pacific at more than 500 miles per hour. Then just five years later, on March 9, 1957, an earthquake measuring 8.3 occurred in the Aleutian Islands generating a tsunami. Waves up to 75 feet high were reported on Umnak Island. The tsunami traveled 2,440 miles across the Pacific, at a speed of just under 500 miles per hour, and first reached Kauai at 9 a.m.

The tsunami to strike the state of Hawai'i on May 23, 1960 was generated from a 8.3 earthquake in Chile. Much of the damage occurred in Hilo, Hawai'i, where 61 people were killed, 537 buildings destroyed and damages totaled over $23 million.

On November 29, 1975 a 7.2 earthquake occurred locally in the area of Kalapana, Hawai'i. The earthquake generated a tsunami with a maximum height of over 47 feet. The earthquake and tsunami took the lives of two campers and caused property damage estimated at $4.1 million.

At 6:49 p.m. on July 17, 1998, an earthquake occurred at the western end of the Bismark Sea and measured 7.0 on the Richter Scale. About 20 minutes later, a tsunami wave crashed ashore and inundated a 20-mile stretch of beach from west of Aitape to the village of Serai. There was a total of three devastating waves. Villagers were crushed in their huts, buried under sand and debris, and many drowned. In all, 2202 people lost their lives and 1000 more were injured. A total of 10,000 survivors lost their homes and personal possessions.

Ancient tsunami reached 4 miles inland

HONOLULU (AP) _ Scientists have determined a gigantic tsunami hit the Big Island 120-thousand years ago.

The wave surged almost four miles inland and deposited fossil-laden sand up to an elevation of at least 16-hundred feet.

The University of Hawaii's School of Ocean and Earth Science and Technology says the tsunami was generated by the Alika Two Landslide, which came down the western slope of nearby Mauna Loa.

The resulting wave surged across a coral terrace, now located at a depth of 14-hundred feet, before moving inland.

The wave left a deposit of smashed-up marine shells, chunks of lava rock, lumps of soil and fragments of coral, all cemented together by what was once coralline sand.

A giant tsunami caused by the collapse of part of Mauna Loa volcano 120,000 years ago surged more than four miles inland and deposited coral at the 1,600-foot level of the Big Island, according to University of Hawaii scientists.

The researchers tied the deposit to similar material at a coral terrace now 1,400 feet below sea level.

The scientists believe the coral deposit is evidence of a so-called megatsunami.

The deposit is 120,000 years old, the same age as the underwater coral terrace and what is known as the Alika 2 Landslide.

The scientists theorize that the landslide, which sent 120 cubic miles of material into the ocean from Mauna Loa, created a megatsunami that swept miles inland. In contrast, the material from the 1980 Mount St. Helens eruption and landslide was less than one cubic mile, the scientists said.

These gigantic landslides occur in Hawaii about every 200,000 years, Fryer said. The largest giant landslide occurred several hundred thousand years ago off Oahu when half of the Koolau Volcano fell off, creating what is now the Windward side of Oahu.

The theory of megatsunamis is controversial among geologist...

Reference:
www.harktheherald.com
http://www.tsunami.org/archivespics.htm
http://www.kpua.net/news.php?id=3097
http://starbulletin.com/2004/09/02/news/story4.html

 

[sage]

here are some astounding news coming from andaman and nicober islands that has been the epicentre of most of the aftershocks.

some of the first pictures coming from the remote southern islands of nicobar chain has shown that
1)some islands have undergone major subsidence losing over 30% of land area.
2)some islands have bodily moved by several hundred metres
3)some islands have disintegrated into several fragments with over 5 km(in one case) of sea seperating them now.

I've seen the pictures before and after and have heard millitary spokesperson of indian government saying this in a local news channel. however I'm pretty hardput to believe this. can such a large geological change possible in so short a time? hopefully more confirmation will come soon regarding the veracity of the statement.

 

[Teslonic]

Thank you all

I'm doing a report on this disaster and your posts have helped me a lot so I just want to say thank you.

Anti siesmic wave weaponry would be a very good idea although nuclear blasts wouldn't do it. The actual wave is a column of water that only rises when the sea floor rises (hits shore) so the time that the wave can be seen is small. I heard that the wave lowered the water level on the beach, before it struck, and so lots of people were drawn to the free fish but then the wave hit.

A percision weapon of any kind, like a missile, would be hard to manage (bulky, expensive, perhaps unsightly) and ineffective against a non-percision disaster like this. We have sensors in the pacific to give us some warning, although many people say that we don't have enough. Animals seem to have a sense of these things. Most of the animals that could got away, some 100 miles in land, to safety.

The Japanese had some experiments where they kept lots of animals in a lab and evacuated the city if all of them started freaking out suddenly. This saved the people a few times, once from a huge earthquake, but it also gave fail often, both when there wasn't an earthquake and not giving an alarm when there was an earthquake. Here's some documentation:

http://news.nationalgeographic.com/news/2003/11/1111_031111_earthquakeanimals.html#main