Well, yesterday was the start of a sequence of earthquakes offshore of San Clemente Island, about 100 km west of San Diego, California. The primary tectonic player in southern CA is the Pacific – North America plate boundary fault, the…
Earthquake Report: Peru
Just a moment ago, there was an intermediate depth Great Earthquake (magnitude M≥8.0) beneath Peru. I was heading to bed at about 1:10 local time (Sacramento, CA) when I noticed a tweet from Dr. Anthony Lomax (presenting his first motion…
Earthquake Report: New Ireland
This region of Earth is one of the most seismically active in the past decade plus. This morning, as I was preparing for work, I got an email notifying me of an earthquake with a magnitude M = 7.5 located…
Earthquake Report: Panamá
There was just now an earthquake beneath Panamá. The major plate boundary in the region is a subduction zone (convergent plate boundary) where the Cocos and Nazca plates dive northwards beneath the Caribbean plate forming the Middle America trench (MAT).…
Earthquake Report: Papua New Guinea
Earlier today, there was an intermediate depth beneath eastern Papua New Guinea (PNG). With a magnitude M = 7.2, this is one of the largest earthquake so far in 2019. Here is the USGS website for this earthquake. Today’s earthquake…
Earthquake Report: Sulawesi, Indonesia
Today I awoke to the USGS earthquake notification service email about an earthquake offshore of Sulawesi, Indonesia. There was an earthquake with a magnitude M 6.8 to the southeast of the Donggala/Palu earthquake from 28 September 2018. Here is the…
18 April 1906 San Francisco Earthquake
Today is the anniversary of the 18 April 1906 San Francisco Earthquake. There are few direct observations (e.g. from seismometers or other instruments) from this earthquake, so our knowledge of how strong the ground shook during the earthquake are limited…
Earthquake Report: central Aleutians
A couple days ago, in my inbox, there was an email from the Pacific Tsunami Warning Center about an earthquake along the Aleutian Islands, near Rat Island, Alaska. However, this earthquake was not along the megathrust subduction zone fault there…
Earthquake Report: Northern Alaska
At shortly before 13:30 today in northern Alaska there was a large earthquake, with a magnitude of M=5.1 (now M 5.0). https://earthquake.usgs.gov/earthquakes/eventpage/ak0193wxcfea/executive Many of us are familiar with the Good Friday earthquake, a megathrust subduction zone earthquake. This earthquake has…
Earthquake Report: Peru
On 01 March 2019 there was an intermediate depth earthquake near the border of Peru and Bolivia. In the past century, this is the first earthquake in this area at this depth. There are some historic quakes to the east,…