* Astronomy

Blobrana · L

RE: Tsunami Facts

Blobrana · L

Japan tsunami created icebergs in Antarctica, research finds

A NASA scientist and her colleagues were able to observe, for the first time, the power of an earthquake and tsunami to break off large icebergs a hemisphere away.
Kelly Brunt, PhD'08, a cryosphere specialist at Goddard Space Flight Centre and colleagues were able to link the calving of icebergs from the Sulzberger Ice Shelf in Antarctica following the Tohoku Tsunami, which originated with an earthquake off the coast of Japan in March 2011. The finding, detailed in a paper published online today in the Journal of Glaciology, marks the first direct observation of such a connection between tsunamis and icebergs.
The birth of an iceberg can come about in any number of ways. Often, scientists will see the towering, frozen monoliths break into the polar seas and work backwards to figure out the cause.
So when the Tohoku Tsunami was triggered in the Pacific Ocean on March 11 this spring, Brunt and colleagues immediately looked south. All the way south. Using multiple satellite images, Brunt, Emile Okal at Northwestern University and Douglas MacAyeal at the University of Chicago were able to observe new icebergs floating off to sea shortly after the sea swell of the tsunami reached Antarctica.

Blobrana · L

Tsunami Warnings, Written in Stone

The stone tablet has stood on this forested hillside since before they were born, but the villagers have faithfully obeyed the stark warning carved on its weathered face: "Do not build your homes below this point!"
Residents say this injunction from their ancestors kept their tiny village of 11 households safely out of reach of the deadly tsunami last month that wiped out hundreds of miles of Japanese coast and rose to record heights near here. The waves stopped just 300 feet below the stone.
Read more

Blobrana · L

Japan's northeast suffered many large past tsunamis

Japan's battered northeastern coast suffered many large tsunamis in the past and nuclear power stations there should have been built to withstand these huge walls of water, a scientist said on Thursday.
In a commentary in the journal Nature, geophysics professor Robert Geller singled out two tsunamis -- the 38-metre Sanriku tsunami of 1896 that killed 22,000, and the Jogan tsunami of 869 that was comparable in size to the March 11 disaster -- which pummelled the very same Tohoku region in the northeast.
Read more

Blobrana · L

Three weeks after being hit by a devastating tsunami, authorities in Japan are starting to consider how they could have been better prepared for the disaster.
Roland Buerk reports from Oirase on Japan's north east coast, where a sea wall proved decisive in protecting citizens.
Read more

Blobrana · L

Tsunami Travel Time Software.

This CD-R contains the latest version of the Tsunami Travel Times software. The new version 3.1 provides installation for both Unix/Linux/MacOSX systems and Windows (InstallShield installation) and is fully ANSI-C/POSIX compatible. The CD-R contains premade global bathymetry grids at 2, 5, 10, 15, 20, 30, and 60 minute resolutions. TTT is now independent of GMT; however GMT is recommended for analysis and plot making.
Read more

Blobrana · L

The Pacific Ring of Fire, a horseshoe-shaped 40,0000km stretch encircling the Pacific Ocean, is said to be the region most susceptible to earthquake. This region with a nearly continuous series of oceanic trenches, volcanic arcs and plate movements has 452 volcanoes and is home to over 75% of the world's active and dormant volcanoes.
Ninety per cent of earthquakes and 80% of the world's largest earthquakes occur along the Ring of Fire. About 80% of tsunamis also happen in the Ring of Fire region. The next most active region, which accounts for 56% of earthquakes and 17% of the largest earthquakes, is the Alpide belt which lies along Java, Sumatra , the Himalayas, the Mediterranean, and then the Atlantic Ocean.
Read more

Blobrana · L

The Pacific is often a source of tsunami activity, because dense oceanic plates slide under lighter continental plates. When the plates fracture, the movement occurring on the seafloor produces a quick transfer of energy from the earth to the ocean. Underwater landslides sometimes associated with smaller earthquakes can also result in a tsunami. Additionally, volcano action an asteroid impacts can produce a tsunami.
Read more

Blobrana · L

Samoa earthquake: a history of tsunamis
Tsunamis like that caused by the Samoa earthquake are among nature's most lethal disasters. We look at some of the worst.

Read more

Tsunami Warning Signs, Facts in Wake of Samoa Quake
In light of Tuesday's tsunami in Samoa and American Samoa, find out how the killer waves are caused, what the warning signs are, and how to respond when a tsunami threatens.

Read more

Blobrana · L

The odds of encountering a tsunami kicked up by an asteroid strike have just plummeted. Best to hope, though, that you're not underneath the almighty splash such an impact could create.
Small impactors hit us far more frequently than larger ones: a 200-metre asteroid hits Earth about every 10,000 years on average, while 10-kilometre objects like the one that probably killed off the dinosaurs strike every 100 million years. Much of the worry over asteroids has centred on the more likely event of a smaller one splashing down in the ocean and triggering a powerful tsunami.
Now simulations to be presented at an asteroid hazard conference in Granada, Spain, this month suggest that small asteroids do not after all pose a major tsunami threat.

Read more