Earthquakes
Magnitude 4.8
Date-Time
* Friday, March 11, 2011 at 16:54:52 UTC
* Friday, March 11, 2011 at 10:54:52 AM at epicenter
* Time of Earthquake in other Time Zones
Location 12.304°N, 87.514°W
Depth 64.3 km (40.0 miles)
Region NEAR THE COAST OF NICARAGUA
Distances 52 km (32 miles) SW of Chinandega, Nicaragua
70 km (43 miles) WSW of Leon, Nicaragua
136 km (84 miles) W of MANAGUA, Nicaragua
1475 km (916 miles) ESE of MEXICO CITY, D.F., Mexico
Location Uncertainty horizontal +/- 25.2 km (15.7 miles); depth +/- 2.2 km (1.4 miles)
The quake struck at 8:24 a.m. local time on Sunday (2324 GMT on Saturday), according to the US Geological Survey.
The epicenter was monitored at 37.9813 degrees north latitude and 141.8492 degrees east longitude, with a depth of 24.8 kilometers (14 miles), the Xinhua news agency reported.
The quake was followed by a 6.6-magnitude aftershock two minutes later.
Japan is still conducting rescue operations in the aftermath of Friday's 8.9-magnitude earthquake, which triggered a 23-foot (7-meter) tsunami and over 50 aftershocks, with many measuring more than 6.0 on the Richter scale.
There are concerns that the death toll from the catastrophic earthquake could exceed 1,800.
"I have no doubt" that the death toll would rise above 10,000 in the prefecture, public broadcaster NHK quoted police chief Takeuchi Naoto as saying.
About 800 deaths had been confirmed so far in Miyagi and other areas in northeastern Japan, which were hit Friday by the quake and a tsunami. No contact could be established with about 10,000 residents of the town of Minamisanriku.
TWS did not receive any reports of damage, however reports of light shaking were received in the city of Los Mochis, Mexico.
The quake hit under 50 miles west of Los Mochis at 7:11 a.m. local time, and struck the very center of the Gulf of California, on the plate boundary.
Sensors indicated the quake was a strike-slip, or side to side motion along the fault-zone.
A 4.7-magnitude aftershock was registered in the same location as the larger quake several hours later.
The USGS data for this quake can be viewed here.
"That's a reasonable number," USGS seismologist Paul Earle told AFP. "Eight feet, that's certainly going to be in the ballpark."
Friday's 8.9 magnitude quake unleashed a terrifying tsunami that engulfed towns and cities on Japan's northeastern coast, destroying everything in its path in what Prime Minister Naoto Kan said was an "unprecedented national disaster."
The quake and its tectonic shift resulted from "thrust faulting" along the boundary of the Pacific and North America plates, according to the USGS.
The Pacific plate pushes under a far western wedge of the North America plate at the rate of about 3.3 inches (83 millimeters) per year, but a colossal earthquake can provide enough of a jolt to dramatically move the plates, with catastrophic consequences.
"With an earthquake this large, you can get these huge ground shifts," Earle said. "On the actual fault you can get 20 meters (65 feet) of relative movement, on the two sides of the fault."
NASA geophysicist Richard Gross calculated that Earth's rotation sped up by 1.6 microseconds. That's because of the shift in Earth's mass caused by the 8.9-magnitude earthquake. A microsecond is one-millionth of a second.
Below is a stunning collection of photographs which show some of the devastation in Japan:

This image from NASA's Aqua satellite shows a major fire raging near the coastal city of Sendai in northeastern Japan after the massive 8.9-magnitude earthquake that struck on March 11, 2011. This image was taken by Aqua's MODIS instrument on March 12.
Photos from NASA's Earth-watching Terra and Aqua satellites paint a stark picture from above of the damage by the massive 8.9-magnitude earthquake and the subsequent tsunami it spawned. They show Japan's northern region, particularly the city of Sendai - which is visible inundated by floodwaters and fires in the satellite views.
The images were taken today (March 12) - one day after the natural disaster as part of NASA's MODIS Rapid Response system, which uses satellites to provide near real-time images of Earth's landmasses every day. The system can snap photos of Japan twice a day, NASA officials said. [Japan Earthquake and Tsunami in Pictures]

NASA's Terra satellite's first view of northeastern Japan flooding following the earthquake and tsunami in northeastern Japan
"At this point, we know that one GPS station moved (8 feet), and we have seen a map from GSI (Geospatial Information Authority) in Japan showing the pattern of shift over a large area is consistent with about that much shift of the land mass," said Kenneth Hudnut, a geophysicist with the U.S. Geological Survey (USGS).