It’s the first time researchers have been able to get geological samples from so far down in an active earthquake area and should give new insights into how faults and earthquakes actually work.
The big surprise was the significant amounts of the mineral serpentine that were found. It’s a soft mineral the geologists think plays a substantial role in the creation of earthquakes.
Some members of the research team describe the finds as the geologic equal to moon rocks. And they’re a hot property with hundreds of requests now coming in from universities and researchers wanting to get their hands, and eyes, on these specimens.
The collection process has extracted about a ton of rock. The samples are 135-foot-long cylinders that have a four-inch diameter and were bored out near Parkfield, Calif. That’s a region of the San Andreas Fault where earthquakes are common, but not too severe. Along with the serpentine, the samples also include large amounts of shale and sandstone.
A 6.8-magnitude earthquake shut down the Kashiwazaki Kariwa nuclear power plant, the world's largest in terms of electricity output resulting in a fire and causing a reactor to spill radioactive water into the sea. Associated Press via Yahoo News
This Thursday (Feb 15) at 10 am Reno, Nevada time, a quarter scale, 110 ft., 4 span bridge section will be shaken by forces twice the intensity of the 1994 Northridge earthquake.
The Network for Earthquake Engineering Simulation (NEES) website has provided links to a variety of resources:
A magnitude 7.7 earthquake occurred in the Indian Ocean about 220 miles from Jakarta, Indonesia. It caused tsunamis which are most likely responsible for the death of at least 100 people and the injury of another 150 people. The earthquake was followed by strong aftershocks.
The Hong Kong Observatory reported that an earthquake of magnitude 6.2 has struck central Indonesia. There are not yet any reports of casualties or damages.
On May 27, a powerful earthquake—centered about ten miles southeast of Yogyakarta—shook Java, Indonesia. It destroyed more than 135,000 houses, leaving 200,000 people homeless, and it killed at least 6234 people, injuring another 46,000. And volcanic activity on nearby Mount Merapi has tripled since the quake, sparking fears of an eruption.
The "ring of fire"
The continents rest on large plates of rock that are slowly moving around the surface of the Earth. Indonesia, a nation of more than 18,000 islands, experiences a lot of earthquakes and volcanic eruptions because it sits along the “ring of fire”—the Pacific Ocean’s zone of active volcanoes and tectonic faults.
Just south of Java, the Australian plate is moving north at two and a half inches each year. Where the Australia plate collides with the Sunda plate—which includes Java—the Australia plate slips under the Java plate in a process geologists call subduction.
Pressure builds up along the fault lines where the plates meet. When the rocks separating the plates suddenly give way, the ground shakes and buckles in what we call an earthquake. Volcanoes are formed when the subducted rock melts and returns to the surface as magma.
How strong was this earthquake?
The United States Geological Survey says the quake measured 6.3 on the Richter scale. This quake didn’t cause tsunamis like the big earthquake in December 2004. But it was shallow—only 6 miles underground—which made the shaking on the surface more intense than other quakes of the same magnitude. And the quake struck at 5:54 am local time, trapping many people in their homes.
How did this earthquake compare to others?
About 500 miles west of Costa Rica, scientists dug deep (and I mean DEEP) into the Earth’s crust. For the first time, layers of pristine igneous rock were retrieved. Their findings included a dark rock called gabbro. Gabbro is an igneous rock formed when molten magma is trapped underneath the Earth’s surface, cools and forms a crystalline mass.
JOIDES Resolution, the drill ship, bored nearly a mile into our planet’s oceanic crust recovering a complete stratified core of the overlaying crust in the Pacific Ocean. Studying gabbro along with crust sections will better inform scientists about the processes pertaining to crust formation and structure, plate tectonics, mountain formation as well as earthquake and volcano triggers.
Douglas Wilson, study co-author from the University of California, Santa Barbara, told LiveScience “This process covers 60 percent of the Earth’s surface, and it’s an ongoing process that has replaced all of the seafloor since 180 million years ago. In terms of understanding the planet, it’s a fundamental process."
There was a 7.7 magnitude earthquake centered in Pakistan on October 8th, 2005 at 8:50am Pakistan time (that's 10:50pm on Friday in Minnesota). The earthquake devastated the region, leaving many villages destroyed and killing thousands in Pakistan and India. It is one of the strongest earthquakes to hit this area in living memory. Pakistan's president Pervez Musharraf described the disaster as the country's "worst-ever."
The earth's continents rest upon large plates of rock that are slowly moving around the surface of the earth. For millions of years, the Indian subcontinent has been slowly moving north towards Europe and Asia (Eurasia). About 40-50 million years ago (mya), India slammed into Eurasia. Because both India and Eurasia were continents the Eurasia crust crumpled upwards, creating the Himalayan mountains. The leading edge of India was eventually forced underneath the continent in a process geologists call subduction. This movement is still happening today. However, as India continues to move slowly north, it gets hung up and energy builds. When enough energy builds up, there are short bursts of movement, releasing this massive energy and shaking and buckling the ground in what we call an earthquake.
In the last hundred years, several other earthquakes of similar strength have struck this region: