Earthquake News and Global Seismic Reports
Very strong earthquake of magnitude 7.5 reported 91 Km SE of Sand Point, Alaska, USA
A magnitude 7.5 earthquake 1 hour 35 minutes ago was reported by the United States Geological Survey (USGS), considered the key international and national agency that monitors seismic activity in the US. The earthquake occurred at intermediate depth of 40 km (25 mi) beneath the epicenter on 19 Oct 12:54 pm (GMT -8) local time. Magnitude and other quake parameters can still change within the next hours as the agency continues to process the seismic data.
Tue, 20 Oct 2020, 08:3808:38 AM | BY: EARTHQUAKEMONITOR
Our monitoring service at VolcanoDiscovery also identified a second report from Indonesia's Meteorology, Climatology, and Geophysical Agency (BMKG) which listed the quake at magnitude 7.7. Other agencies reporting the same quake include INGV (magnitude 7.4), European-Mediterranean Seismological Centre (EMSC) (magnitude 7.5), GeoAu (magnitude 7.6), German Research Centre for Geosciences in Potsdam (GFZ) (magnitude 7.5).
Based on the preliminary seismic data, the quake should have been felt by everybody in the area of the epicenter. In those areas, dangerous ground shaking occurred with the potential to inflict moderate to heavy damage to buildings and other infrastructure.
Towns and cities near the epicenter that are likely to be affected include Sand Point (pop. 1,100) in 92 km (57 mi) distance with strong ground shaking expected according to preliminary calculations, Perryville (pop. 100) in 143 km (89 mi) distance, strong ground shaking expected, King Cove (pop. 1000) in 175 km (109 mi) distance, strong ground shaking expected, Nelson Lagoon (pop. 100) in 178 km (110 mi) distance, strong ground shaking expected.
This story will be updated soon by VolcanoDiscovery. If you’re in the area, please send us your experience through our reporting mechanism. This will help us provide more first-hand updates to anyone around the globe who wants to know more about this quake.
Go to: Details about this quake
Update Mon, 19 Oct 2020, 22:32A tsunami warning previously issued automatically has been lifted. There is no longer any significant threat of tsunamis from this quake.
Except for minor sea level fluctuations in the area near the epicenter, no significant wave action has been detected.
Update Mon, 19 Oct 2020, 22:48The quake follows the massive 7.8 quake, which hit the same area on 22 July earlier this year, but didn't cause significant damage, mainly due to the extremely low density of population.
Therefore, we don't expect any major damages from this quake either, although a report mentions that some buildings collapsed in Unga, a small settlement about two miles west of Sand Point.
Update Tue, 20 Oct 2020, 08:38According to detailed calculations of USGS, yesterday's magnitude 7.5 quake was a large aftershock of the M 7.8 quake on 22 July earlier this year.
Tectonic summary (USGS):
The earthquake occurred as the result of strike-slip faulting near the subduction zone interface between the Pacific and North America plates, either within the upper (North America) Plate or within the downgoing (Pacific) slab.
The preliminary focal mechanism solution indicates rupture occurred on either a moderately dipping right-lateral strike-slip fault striking towards the NNW or on a steeply dipping left-lateral strike-slip fault striking towards the east, and therefore that this earthquake was not a thrust event on the plate interface itself.
At the location of this event, the Pacific plate converges with North America to the northwest at a rate of about 64 mm/yr, subducting at the Alaska-Aleutian Trench 100 km to the southeast of the earthquake.
If you were or still are in this area during the quake help others with your feedback and file a quick report here.
I felt this quake
Date & time: Mon, 19 Oct 20:54 UTC
Depth: 33.3 km
Epicenter latitude / longitude: 54.6079°N / 159.6552°W
Primary data source: USGS