Earthquakes in the United States: seismic activity report for the past day

The United States constantly experiences various types of natural hazards, among which earthquakes are one of the most studied by the scientific community. During late January, multiple seismic events of different magnitudes were recorded across various regions of the country, according to official data from the United States Geological Survey (USGS). This report details the observed tremors, including information about their epicenters, magnitudes, and specific locations.

24-Hour Seismic Activity Overview

In one day, North America and the Caribbean experienced 27 earthquakes with magnitudes greater than 2.5. Of these, nine occurred within U.S. territory or its insular jurisdictions. The strongest event reached a magnitude of 4.2 and was located near Black Eagle, Montana, standing out among the other recorded tremors for its higher relative intensity.

The geographic distribution of these earthquakes ranged from Alaska in the north, through several continental states such as Colorado, Texas, New Mexico, and Oregon, to Puerto Rico and Hawaii. Each was carefully recorded by USGS monitoring stations, with precise data on UTC time and local time.

Technical Details: Epicenter and Magnitude of Each Event

The detected earthquakes had the following specific characteristics:

In Alaska:

• 23 kilometers west of Akhiok: magnitude 2.8, recorded at 11:52 UTC
• 28 kilometers northwest of Happy Valley: magnitude 2.6, at 11:44 UTC
• 40 kilometers east of Pedro Bay: magnitude 3.0, at 02:07 UTC
• 194 kilometers southeast of Akutan: magnitude 3.1, at 02:02 UTC
• 74 kilometers north of Yakutat: magnitude 3.7, at 22:59 UTC
• 61 kilometers east of Sand Point: magnitude 3.5, at 21:01 UTC
• 59 kilometers southeast of Sand Point: magnitude 3.3, at 20:25 UTC
• 94 kilometers north of Yakutat: magnitude 3.5, at 18:37 UTC
• 104 kilometers southeast of McCarthy: magnitude 3.1, at 18:36 UTC
• 47 kilometers northwest of Valdez: magnitude 2.6, at 15:16 UTC
• 64 kilometers southeast of Adak: magnitude 2.6, at 13:21 UTC
• 288 kilometers southwest of Adak: magnitude 3.8, at 12:57 UTC

In Montana:

• 8 kilometers northeast of Black Eagle: magnitude 4.2, at 19:41 UTC on January 29 (the strongest)
• 5 kilometers northwest of Malmstrom Air Force Base: magnitude 2.7, at 00:46 UTC

In Colorado:

• 29 kilometers south of Weston: magnitude 2.8, at 11:06 UTC
• 32 kilometers southwest of Segundo: magnitude 2.5, at 11:06 UTC

In other continental states:

• Texas (12 km west of Stanton): magnitude 2.7, at 07:25 UTC
• Texas (35 km northwest of Toyah): magnitude 2.5, at 18:32 UTC on January 29
• Texas (10 km southeast of Pearsall): magnitude 2.6, at 17:02 UTC on January 29
• New Mexico (32 km north of Cimarron): magnitude 3.9, at 07:20 UTC
• Oregon (259 km southwest of Pistol River): magnitude 3.5, at 05:30 UTC

In Caribbean territories:

• Puerto Rico (5 km east-southeast of Maricao): magnitude 3.1, at 07:53 UTC
• Puerto Rico (133 km northeast of Vieques): magnitude 3.3, at 16:41 UTC on January 29

The San Andreas Fault: The Epicenter of Seismic Risk in California

The San Andreas Fault is one of North America’s most significant geological features, extending approximately 1,300 kilometers across California. This fault line marks the contact boundary between two massive tectonic plates: the Pacific Plate and the North American Plate. Friction and relative movement between these rock masses generate constant seismic activity, making it a continuous subject of scientific research.

Seismologists warn of the potential occurrence of a catastrophic event in the future known as the “Big One,” a quake of magnitude 8 or higher. If it occurs, this seismic event could trigger widespread devastation across large geographic areas, especially in densely populated urban centers like Los Angeles and San Francisco.

California’s seismic history records major past earthquakes. The most notable was the 1906 San Francisco earthquake, which reached a magnitude of 7.8, and the Fort Tejon earthquake of 1857, estimated at approximately 7.9 magnitude, both according to USGS archives. Facing this ongoing threat, California authorities regularly conduct evacuation drills, review structural safety protocols, and develop educational campaigns to ensure the population knows the protective measures to take before, during, and after any major quake.