75th Aftershock of Magnitude 6 or Higher Hits Near Japan

A magnitude 6.7 earthquake rocked Japan today, the 75th aftershock of at least magnitude 6.0 from the devastating magnitude 9.0 quake on March 11, according to the U.S. Geological Survey (USGS). The earthquake data is preliminary and subject to revision.

Japan has been rocked by hundreds of aftershocks since the deadly Tohoku earthquake, the biggest in Japan's recorded history . The aftershocks have been so plentiful that the world's premier earthquake-measurement service has since modified its alert system to filter out the smaller aftershocks. The largest aftershock was a magnitude 7.9 quake that struck less than an hour after the main shock. A magnitude 7.7 also struck that day. A magnitude 7.1 aftershock struck on April 7. [ When Will the Aftershocks in Japan End? ]

The number of aftershocks seems staggering, but geologists are not surprised, especially for such large mainshock .

The rule of thumb for aftershock strength is that the biggest aftershock will be about one magnitude smaller than the mainshock.

The latest aftershock struck about 54 miles (88 kilometers) east of Honshu. The quake ruptured 20 miles (32 km) below the Earth's surface.

Since the main quake off Japan's northeastern coast, hundreds aftershocks have shaken the island of Honshu, Japan's largest and home to 100 million people. Today's aftershock was caused by thrust faulting near the Japan Trench, the boundary between the Pacific and North America tectonic plates (the huge, moving slabs of the Earth's crust). Thrust faulting happens when one tectonic plate dives under another. In this case, the Pacific plate is diving under the North America plate.

Before the magnitude 9.0 earthquake, only nine magnitude 7.0 or greater earthquakes had ruptured in this subduction zone since 1973.

Japan Earthquake and Tsunami, the Despair and emerging Hope ...

Article by Sky Kim

At 05:46 GMT (14:46 in Japan) on march 11 2011, a massive earthquake, 8.9 on the Richter scale, unleashes a huge tsunami which crashes through Japan’s eastern coastline, sweeping buildings, boats, cars and people miles inland.Five days since a massive earthquake and tsunami hit Japan last Friday, the casualties and damage are still mounting. In spite of the multiple historical disasters, enormous casualties and continuing thread, there is emerging hope within the despair from the attitude of Japaneses facing this crisis, news of survivors and the help from all over the world. Japanese is gets together and whole world gets together to overcome the natural disaster. Here are the quotes we can take glance of Japan’s despair and emerging Hope within it.

I hesitated first time, but I decided to volunteer not to regret in the rest of my life.~ A Volunteer For The Last 70 In Fukushima Reactor59 year old man works in a branch nuclear reactor facility. He was waiting for retire on coming September. He volunteered the Fukushima nuclear plant cooling work at life threading hazards. The fate of Japan depends on the 70 people left in Fukushima nuclear plant.

I hope that those affected by the earthquake will not give up hope and will strive to survive, while taking care of their health.~ Akihito

Japan’s Emperor Akihito, in a recorded message, asked the Japanese people not to give up hope and to reach out to each other in this time of great crisis. He urged the earliest relief be delivered to those in northeast Tohoku region who are still suffering after the earthquake and tsunami, and asked those at the damaged Fukushima Daiichi plant to do all that they could to avoid a worsening of the situation.The address lasted roughly five minutes, and all major television stations simultaneously broadcast the recorded message at 4.30 p.m. on Wednesday.

Your hometown is your hometown. They’ll rebuild. I don’t know if the young people will come back, but they’ll rebuild! ~ Miyuki Kanno (Resident Near Kesen)Kesen turns to virtually a ghost town after Japan Earthquake and Tsunami.Miyuki Kanno, who lives a few miles (kilometers) away, rode his bicycle down a mud- and water-choked section of road looking for information about missing relatives. He guessed it would take 20 years for Kesen to come back.

Today and tomorrow there is still hope that we will find survivors~ Pete Stevenson (Head Of The British Rescue Crews)One woman’s body is found wedged beneath a refrigerator in a two-story home pushed onto its side. Pete Stevenson, head of the British rescue crews said also “We’ll just keep on carrying out the searches.” on March 16, five days after Japan earthquake and tsunami.

Journal of geophysical research

The National geographic magazine

Earthquakes

Encyclopedia of planetary sciences

International handbook of earthquake and engineering seismology