Acehtsunami

Scientists in Geoscience Australia will activate the country’s highly advanced tsunami warning system in upcoming months which will allow scientists to make accurate predictions on both when tsunamis may happen and on where they may hit.

According to scientists, it is a world-first system, the first seismic array designed to enable authorities to make accurate predictions on tsunamis. The system being installed in the red dust of the Pilbara region in Western Australia will monitor earthquakes that occur around the Indian Ocean and along the Indonesian archipelago. The seismic array is a network of interconnected seismographs that measure and record the force and duration of earthquakes. They are arranged in a geometric pattern to increase sensitivity to events underground.

Readings from the tearing of the Earth will be beam, in real time, back to the tsunami warning center in Melbourne and Geoscience Australia in Canberra. Australia is located on the northwest, northeast and east by some 8,000 km of active tectonic plate boundary capable of generating tsunami. One-third of all earthquakes worldwide occur along these boundaries. The impact of a tsunami hitting vulnerable low-lying areas of the Australian coast could be significant.

A moderate earthquake struck Philippine island of Luzon on 26th July early Tuesday morning .The seismologists and witnesses said that “there were no immediate reports of damage or casualties”.

The 5.9-magnitude earthquake at 1.15 a.m. local time (1715 GMT Monday) was centered about 3.5 kilometers (2.1 miles) west of San Marcelino, a small city in the province of Zambales. The earthquake struck about 30 kilometers (18 miles) deep, making it a low magnitude earthquake, according to the Philippine Institute of Volcanology and Seismology (PHIVOLCS).

The Philippines is on the so-called ‘Pacific Ring of Fire’, an arc of fault lines circling the Pacific Basin which is prone to frequent and large earthquakes. Volcanic eruptions also occur frequently in the region. In July 1990, a powerful 7.8-magnitude earthquake struck the densely populated island of Luzon, killing at least 2,412 people and injuring thousands more. It was one of the most deadly earthquakes in the Philippines in recent history.

On May 19, 2011 landslide at Porcupine Bay, Washington produced a small tsunami. The tsunami traveled across the Spokane River, generating strong waves on the opposite shore that damaged a camp. Landslides in the United States take place in all 50 States. The core regions of landslide occurrence and potential are the coastal and mountainous areas of California, Oregon, and Washington, the States comprising the inter mountain west, and the mountainous and hilly regions of the Eastern United States. Alaska and Hawaii also experience all types of landslides.

In 1958, a much larger landslide produced a tsunami with the world’s highest known run-up in Lituya Bay, Alaska. On the night of July 9, 1958 an earthquake along the Fair-weather Fault in the Alaska Panhandle loosened about 40 million cubic yards (30.6 million cubic meters) of rock high above the northeastern shore of Lituya Bay. This mass of rock plunged from an altitude of approximately 3000 feet (914 meters) down into the waters of Gilbert Inlet.

The impact generated a local tsunami that crashed against the southwest shoreline of Gilbert Inlet. The wave hit with such power that it swept completely over the spur of land that separates Gilbert Inlet from the main body of Lituya Bay. The wave then continued down the entire length of Lituya Bay, over La Chaussee Spit and into the Gulf of Alaska. The force of the wave removed all trees and vegetation from elevations as high as 1720 feet (524 meters) above sea level. Millions of trees were uprooted and swept away by the wave. This is the highest wave that has ever been known.

Tsunami made a great disaster in northern Japan. The destruction of Japan resulted in great economic meltdown of the country. Major disasters always require a huge amount of international support to provide relief and long term recovery efforts.
The report explains that it will take years to recover from the economic meltdown in Japan.

Predictable tsunami warning systems rely on estimates of an earthquake’s magnitude to determine whether a large tsunami will be generated. Earthquake magnitude is not always a reliable indicator of tsunami potential, however.

March2011: Incident of quake (8.9-magnitude) in Fukushima, Japan on March 11, 2011 caused more than 10 thousand casualties, which is next to World War II for the country. Incident of quake (6.8-magnitude) in Myanmar (Burma), Thailand & China on March 24, 2011.

Review on April 17, 2011: Incident of mild to moderate quake along with tsunami is possible within the span of April 23 until May 3, but degree of devastation will be much lower than the incident happened on March 11, 2011 in Japan.

A strong earthquake with a preliminary magnitude of 7.4 has hit the Pacific Ocean off southern Japan.

Japan’s Meteorological Agency has alarmed a tsunami warning from the quake, which occurred about 130 kilometers off the southern coast of Chichi Island in the Pacific Ocean. The offshore quake hit at a depth of 10 kilometers.

The agency issued a tsunami alert of up to two meters for nearby islands and warnings of milder tsunami for the southern coasts on the main Japanese island.

Every 15 months or so, an unfelt earthquake occurs in western Washington and travels northward to Canada’s Vancouver Island. The episode typically releases as much energy as a magnitude 6.5 earthquake, but it does so gradually over a month.

New technology is letting University of Washington researchers get a much better picture of how these episodic tremor events relate to potentially catastrophic earthquakes, perhaps as powerful as magnitude 9, that occur every 300 to 500 years in the Cascadia subduction zone in western Washington, Oregon and British Columbia.

“Depending on where the tremor is, a different part of the fault is being loaded,” said Abhijit Ghosh, a UW doctoral student in Earth and space sciences, who is presenting the most recent findings Monday (Dec. 13) at the annual meeting of the American Geophysical Union in San Francisco.

Tsunami Saipan Pentathlon Meet has been held at Kan Pacific Swimming pool and around 60 swimmers participated in it.

The one-day meet grouped participants from Tsunami Swimming Center Saipan and Saipan Swim Club under four categories for five events: 50m butterfly, 50m backstroke, 50m breaststroke, 50m freestyle, and 200m individual medley.
The qualifying times and respective scores were allotted to them. The details are as follows: In the U8 50m butterfly and 50m backstroke, the qualifying times were the same at one minute and 10 seconds or lower; 55 seconds for 9 to 10 age group; 45 seconds for 11 to 12; and 43 seconds for 13-and-above.

Tsunamis can have wavelengths ranging from 10 to 500 km and wave periods of up to an hour. As a result of their long wavelengths, tsunamis act as shallow-water waves. A wave becomes a shallow-water wave when the wavelength is very large compared to the water depth. Shallow-water waves move at a speed, c, that is dependent upon the water depth and is given by the formula:

where g is the acceleration due to gravity (= 9.8 m/s²) and H is the depth of water.

In the deep ocean, the typical water depth is around 4000 m, so a tsunami will therefore travel at around 200 m/s, or more than 700 km/h.

For tsunamis that are generated by underwater earthquakes, the amplitude (i.e wave height) of the tsunami is determined by the amount by which the sea-floor is displaced. Similarly, the wavelength nd period of the tsunami are determined by the size and shape of the underwater disturbance.

As well as travelling at high speeds, tsunamis can also travel large distances with limited energy losses. As the tsunami propagates across the ocean, the wave crests can undergo refraction (bending), which is caused by segments of the wave moving at different speeds as the water depth along the wave crest varies.

The 7.7 magnitude earthquake and resulting tsunami that struck Monday off of Pagai Selatan Island, one of the Mentawai Islands off the west coast of Sumatra Island, have reportedly left 400 people dead, hundreds still missing, and an estimated 13,000 homeless.

Farther away from the epicenter, the tsunami wave dissipated rapidly to increases of only 10 to 40 cm in amplitude as recorded at tide gauges on Cocos Island, Enggano Island, Tanahbalah Island, Padang, Hanimaadhoo, Rodrigues, and Port Louis, for example. Assistant Director General of UNESCO and Executive Secretary of the Intergovernmental Oceanographic Commission Dr.

Wendy Watson-Wright, confirmed that the alerts issued from the Pacific Tsunami Warning Center the Japanese North West Pacific Tsunami Advisory Center, and the Indonesian Tsunami Early Warning System functioned as intended to alert governments of the situation within minutes of the natural disaster. The PTWC cancelled the regional watch 2 hours and 15 minutes after the earthquake. The center cautioned however that rapid changes and variations in currents in the region could continue for several hours following the seismic event and that boats and coastal structures should monitor the advice of local authorities.

Indonesia to start rebuilding tsunami-hit areas next year is set to begin renovation and remedy in tsunami-devastated areas of West Sumatra next year, including the relocation of 15,000 people, a minister reported.

National Development Planning Minister Armida Alisjahbana informed a press conference that the government had broadened emergency relief work which should end on Monday for two weeks.

“The reconstruction and rehabilitation will kick off in 2011,” she said. The tsunami generated by 7.7 magnitude earthquake in Mentawai islands off the west coast of Sumatra on Oct. 25 killed 447 people with 57 others missing and 15,353 people dislocated as the tsunami destroyed 517 houses, said Armida.