The United States Geological Survey recorded
a Magnitude 4.5 Earthquake at a depth of 16.7 km, roughly 6 km to the northeast of the city of Port Oreford in Curry County, Oregon,
at about 1.45 am local time (about 9.45 am GMT) on Saturday 30 November 2019. This was not a large quake, and no damage or
injuries have been reported, but it was across much of southwest Oregon and in parts of northern California.
The approximate location of the 30 November 2019 Curry County Earthquake. USGS.
Oregon
forms the southern part of the Cascadia Subduction Zone, along which
the Juan De Fuca plate, which underlies part of the northeast Pacific,
is being subducted beneath the western margin of the North American
Plate. This
is not a smooth process, and the two plates frequently stick together
then break apart again as the pressure builds up, causing Earthquakes in
the process. The
heat and pressure within the Earth also slowly melts the subducting
plate, liquefying more volatile minerals which then rise through the
overlying North American Plate as magma, fuelling the volcanoes of
America's Pacific Northwest.
Subduction along the Cascadia Subduction Zone. Kathleen Cantner/American Geosciences Institute/Earth Magazine.
Witness
accounts of quakes can help geologists to understand these events and
the rock structures that cause them. If you felt this quake (or if you
were in the area but did not, which is also useful information) you can
report it to the United States Geological Survey here.
See also...
