A major earthquake struck just off the eastern coast of the Philippines on Friday, Aug. 31. According to theUnited States Geological Survey , the temblor measured 7.6 in magnitude (initial reports registered the quake as 7.9 but it was later downgraded slightly) and had an epicenter just 60 miles east of Sulangan in the Philippine Sea around the Philippine Trench, along the Philippine Sea plate.
* The USGS listed this earthquake at a depth of 21.7 miles (34.9 kilometers), which is considered a somewhat shallow depth for a quake.
* The location of the quake's epicenter was on the sea floor in a subduction zone. Subduction zones are plate boundaries where one plate subducts or dives beneath another plate. Tsunamis are generated by earthquakes in subduction zones. The massive 9.0 magnitude earthquake off the coast of Japan in March 2011 occurred in a subduction zone.
* Accuweather.com reported that a tsunami warning was initially issued for Indonesia, the Philippines, Bealau, Japan, Yap, Taiwan, Guam, Papua New Guinea and Northern Mariana. That warning was later canceled for all areas except Indonesia, the Philippines and Bealau.
* A tsunami watch was also issued for Hawaii but was later canceled. A watch that was issued for Kosrae, Chuuk, Marcus Island, the Marshall Islands, Wake Island, Pohnpei, Russia and Nauru remained in effect.
* The Associated Press reported at least one death following the quake. This fatality was reportedly caused by a house collapse. The confirmed death was that of a 54-year-old woman. Her 5-year-old grandson, who was in the house with her, was injured and was being treated at a local hospital.
* Residents affected by the quake and the tsunami warnings were urged to seek higher ground and remain vigilant following the quake and subsequent aftershocks.
* Earthquakes are not uncommon in this region and quakes centered around the Philippine plate have been known to cause tsunamis and great destruction. According to the USGS, the Japanese earthquakes known as the 1923 Kanto earthquake, the 1948 Fukui and the 1995 Kobe quakes occurred along the boundaries of the Philippine plate.
* Friday's quake was followed by several smaller aftershocks that measured in the 4- and 5-magnitude range. According to the website Earthquake-report.com , those living in the region reported homes and furniture shaking and swaying as well as dishes rattling on walls. Some reports included seeing chandeliers swaying and people panicking then running into the streets in some cities.
Tammy Lee Morris is certified as a Community Emergency Response Team (CERT) member and is a trained Skywarn Storm Spotter through the National Weather Service. She has received interpretive training regarding the New Madrid Seismic Zone through EarthScope -- a program of the National Science Foundation. She researches and writes about emergency preparedness, earthquakes, volcanoes, tornadoes, weather and other natural phenomena.