Small quake strikes off Farallon de Pajaros
A small earthquake occurred near Farallon de Pajaros late Thursday, according to the U.S. Geological Survey, registering 4.5 on the Richter scale.
In its report, the USGS National Earthquake Information Center said the quake occurred at about 11:38pm and was located about 135 miles west-northwest of Farallon de Pajaros, 250 miles northwest of Agrihan, 465 miles north-northwest of Saipan, and 560 miles north of Guam.
The earthquake occurred at about 330.4 kms beneath the seabed.
The quake is the 11th in the Marianas region within almost three weeks.
Last Saturday, a 6.6 quake just 55 miles north of Saipan shook the islands, causing items to fall from household and store shelves and alarming residents.
The Emergency Management Office immediately dismissed fears of a possible tsunami, after consulting with the Pacific Tsunami Warning Center.
The threshold for the Pacific Tsunami Warning Center to issue a tsunami watch or alert is if the magnitude of the quake registers at 7.0 or higher.
USGS geologist James Quick said during a recent presentation that the recent series of earthquakes are normal, considering the geologic setting of the islands.
“You’ve had a number of earthquakes, it’s normal for the geologic setting that you’re in. It’s only that you’ve had a little more than normal, but these things are statistical, so every 10 years or so, you’d expect in this area—based on your history—to have a magnitude of 6.0 or greater,” he said.
Fellow USGS geologist Chris Waythomas also indicated that recent quakes may be favorable for the region, citing that the frequent small earthquakes relieve the stress that builds up over time along the cracks of the Marianas Trench.
“Areas along trenches with no earthquakes for a long time…these are candidates for large earthquakes,” he said.
Waythomas said a quake as strong as the 9.9 temblor that happened off the coast of Sumatra in late December may affect other parts of the world, possibly hitting little faults under stress and loosening them up.
The recent quakes also have no “direct relation” to the ongoing Anatahan eruption but both are part of the same subduction system, resulting from the movement of the Pacific and Philippines plates under the seabed.
