Indonesia:Padang Earthquake (September 30, 2009) Explained

Padang Earthquake (September 30, 2009) and Banda Aceh quake (December 26, 2004) Explained

Indonesia lies on the Pacific Ring of Fire. Consequently it is an area great crustal instability. Today's earthquake of magnitude 7.6 struck at sea at 10:16 UTC at a depth of 87 kilometres (54 miles), 53 kilometres northwest of Padang city in West Sumatra province, the United States Geological Survey reported. This was followed by another quake of magnitude 5.5 at 10:38 UTC.
The great Indo-Australian Plate (Indian Plate) underlies the Indian Ocean and Bay of Bengal and is drifting north-east at an average of 6 cm/year (2 inches per year). The Indo-Australian Plate (Indian Plate) subducts the Burma Plate (Eurasian Plate) at the Sunda Trench. Padang city lies close to this subduction zone. A megathrust fault is the boundary between a subducting and an overriding plate. A megathrust earthquake is produced by a sudden slip along this fault.

The town of Padang has been devastated. At the time of writing 75 people are reported dead with thousands of people trapped under collapsed buildings.

The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred with an epicentre off the west coast of Sumatra (off Banda Aceh). The 9.15 magnitude quake, had its epicentre roughly 600km northwest of Padang.
c 1,600 km (994 mi) of faultline slipped (or ruptured) about 15 m (50 ft) along the subduction zone where the India Plate slides (or subducts) under the overriding Burma Plate (Eurasian Plate). The earthquake triggered a series of devastating tsunami along the coasts of most landmasses bordering the Indian Ocean, killing nearly 230,000 people in eleven countries, and inundating coastal communities with waves up to 30 meters (100 feet) high. Coastal locations in Indonesia, Sri Lanka, India, and Thailand suffered most.

Italian TV Channel SKY TG24 Video of Abruzzo Earthquake Damage-6/4/09

Italy: Video of Earthquake scene in Central Italy around L'Aquila in the Apennines (6/4/09)

More than 100 people are believed dead and as many as 50,000 are left homeless after an earthquake hit L'Aquila and other towns in central Italy. About 1,500 people were injured and many people are still missing as rescuers search desperately for survivors trapped beneath rubble. The 6.3-magnitude quake struck at 0330 (0130 GMT) close to L'Aquila

Tectonic Summary

The April 6th 2009 earthquake in Central Italy occurred as a result of normal faulting on a NW-SE oriented structure in the central Apennines, a mountain belt that runs from the Gulf of Taranto in the south to the southern edge of the Po basin in northern Italy. Geologically, the Apennines are largely an accretionary wedge formed as a consequence of subduction. This region is tectonically and geologically complex, involving both subduction of the Adria micro-plate beneath the Apennines from east to west, continental collision between the Eurasia and Africa plates building the Alpine mountain belt further to the north and the opening of the Tyrrhenian basin to the west. The evolution of this system has caused the expression of all different tectonic styles acting at the same time in a broad region surrounding Italy and the central Mediterranean. The April 6th, 2009 earthquake is related to normal faulting and the east-west extensional tectonics that dominate along the entire Apennine belt, primarily a response to the Tyrrhenian basin opening faster than the compression between the Eurasian and African plates.(USGS)

Earthquake strikes northeast tip of Indonesia's Sulawesi Island (11/2/09)-geological background

A strong earthquake measuring 7.0 on the Richter struck off the northeast tip of Sulawesi island Indonesia. Indonesia -a country of over 230 million people-suffers frequent earthquakes due to its location on the Pacific Ring of Fire. The Ring of Fire has 452 volcanoes and is home to over 75% of the world’s active and dormant volcanoes. The epicenter was located about 320 kilometers north-northeast of the town of Manado, the US Geological Survey said.

Northeastern Indonesia is characterized by complex tectonics in which motions of numerous small plates are accommodating large-scale convergence between the Philippine Sea and Sunda plates. In the region of today's earthquake, the Philippine Sea plate moves west-northwest with respect to the Sunda plate at a velocity of about 62 mm/year. Locally, arc-arc collision is occurring between the Sangihe and Halmahera micro plates, wedging between them the Molucca Sea micro plate, which subducts beneath both (i.e. to the east and west) and forms an inverted-U-shaped seismic zone. Seismicity within the Molucca Sea plate is active to depths of approximately 260 km to the east and 400 km to the west. The tectonic setting of this region is unique in that it is the only global example of an active arc-arc collision consuming an oceanic basin via subduction in two directions.
The earthquake occurred approximately 30 km off the western coast of the Pulau Salebabu (Indonesia) in an area that has seen large earthquakes in the past. Since 1986, there have been two earthquakes with magnitude greater than 7 in this region.(USGS)

Japan:Threat To Tokyo as Mount Asamo Volcano erupts

Mount Asamo has erupted near Tokyo, Japan covering parts of the Japanese capital with ash. So far there have been no reports of casualties. There is no sound on some of this video. Mount Asama lies about 90 miles northwest of Tokyo. Japan lies on the Pacific Ring of Fire.

A major earthquake or volcanic eruption could destroy the financial district of Tokyo and wreck the world's financial system.

How well prepared is San Francisco for a large earthquake?

The San Francisco earthquake of 1906 killed at least 3,000 people. It was of magnitude 7.9. 200,000 people were left homeless. Fires that raged through San Francisco in the wake of the earthquake destroyed 28,000 buildings.

On the basis of research conducted since the 1989 Loma Prieta earthquake, U.S. Geological Survey (USGS) and other scientists conclude that there is a 70% probability of at least one magnitude 6.7 or greater quake, capable of causing widespread damage, striking the San Francisco Bay region before 2030. Major quakes may occur in any part of this rapidly growing region. This emphasizes the urgency for all communities in the Bay region to continue preparing for earthquakes...

San Francisco is not prepared for an earthquake of magnitude 7.9. Since 1906, the population of the Bay Area has grown from about 700,000 to about 7 million people . Building standards are higher now. However many buildings are still not adequately reinforced. Some hospitals such as The San Francisco General would be at risk as would many schools. Whilst efforts have been made to strengthen some bridges- to withstand earthquakes- grave doubts must exist until these bridges are tested by a powerful quake.
A major upgrade of the water system will not be completed before 2015. If a massive earthquake were to strike now huge damage would be inflicted on water networks.

If an earthquake on the scale of the 1906 quake were to occur it is estimated that approximately 40,000 office buildings would be destroyed in areas concentrated along the fault zones of San Francisco, San Mateo, Santa Clara County, Alameda and Oakland. The Association of Bay Area Governments has estimated that more than 150,000 uninhabitable residences will occur in a M7.9 repeat of the 1906 earthquake or a M6.9 rupture of the entire Hayward fault. The East Bay I-880 corridor along the Hayward fault would experience the most proportional property damage of the entire Bay area.
The worst case scenario for the Bay Area, is estimated to result in about 5800 fatalities if it strikes during working hours. Some how I think that these figures are an underestimate of the likely number of deaths.
San Francisco’s financial district, is also vulnerable to large earthquakes on both sides of the Bay.
It is estimated that property losses could be up to 300 billion dollars.

In summary many bridges, hospitals, schools, and buildings have not been adequately upgraded
If the buildings are destroyed, their gas and water lines could be seriously damaged, making the likelihood of fire very substantial. San Francisco is not adequately prepared.