On October 4, 2024, an earthquake measuring 1.6 occurred 37 miles east of Chenega Bay, Alaska, at a depth of 12.1 miles. The Southcentral Alaska region is geologically active, influenced by the Pacific and North American tectonic plates, and has a history of significant seismic events including the 1964 M9.2 earthquake.
On October 4, 2024, an earthquake with a magnitude of 1.6 was recorded 37 miles east of Chenega Bay, Alaska, at precisely 5:14:30 AKDT (13:14:30 UTC). The震动 occurred at a depth of approximately 12.1 miles (19 km). This seismic event, yet to be verified by a seismologist, is located 46 miles south of Tatitlek, 57 miles northwest of Middleton Island, and 121 miles southeast of Anchorage, among other notable geographic markers in the vicinity. The tectonic activity in Southcentral Alaska primarily arises from a variety of geological interactions. The most powerful seismic activities stem from the megathrust fault, which represents the meeting point of the subducting Pacific Plate and the overlying North American Plate. This fault line was responsible for the historic 1964 M9.2 Great Alaska Earthquake, recorded as the second largest earthquake ever globally. Additionally, intermediate-depth earthquakes emerge from the Wadati-Benioff Zone, a region where the Pacific Plate sinks beneath the North American Plate, typically below 20 miles (32 km). Significant earthquakes, such as the M7.1 events in 2016 and 2018, demonstrate the region’s seismic volatility and have led to substantial infrastructural damage. Crustal seismicity is further attributed to multiple sources, including faults in the Cook Inlet basin. Among the notable events is the 1933 M6.9 earthquake, known for its severe impact on Anchorage. The Castle Mountain Fault, located north of Anchorage, has geological indications of recent activity and is linked to past earthquakes, such as the M5.6 Sutton Earthquake in 1984. Furthermore, the diffuse seismic activity between Cook Inlet and the Denali Fault may signify a complex zone of deformation influenced by the Bering microplate and the southern Alaska block. This area, characterized by various thrust faults, witnessed the M7.0 earthquake in 1943, underscoring the significance of this dynamic geological landscape.
The geological setting of southern Alaska is characterized by its active seismicity due to the interaction of several tectonic plates. The region is particularly known for the megathrust fault resulting from the subduction of the Pacific Plate beneath the North American Plate, which gives rise to some of the largest recorded earthquakes. The unique tectonic environment, including the presence of the Wadati-Benioff Zone and crustal faults, contributes to frequent and varied seismic events, making it a critical area of study for understanding earthquake mechanics and hazards. Historical events serve as reminders of the seismic risks posed, emphasizing the importance of ongoing monitoring and research in the region.
In summary, the recent magnitude 1.6 earthquake near Chenega Bay highlights the ongoing tectonic activity in Southcentral Alaska, which results from complex interactions between various geological features. The region’s history of significant earthquakes, such as the 1964 Great Alaska Earthquake, serves to illustrate the potential for large seismic events and reinforces the importance of continued observation and research in understanding the risks and underlying mechanics of such occurrences.
Original Source: earthquake.alaska.edu
