Magnitude 1.6 Earthquake Near Chenega Bay, Alaska on October 4, 2024

A magnitude 1.6 earthquake occurred 37 miles E of Chenega Bay, Alaska, on October 4, 2024, at 05:14:30 AKDT. The seismic event has not been reviewed, occurring at a depth of 12.1 miles. Southern Alaska’s tectonic setting is marked by the Pacific subduction beneath North America, with historical earthquakes indicating ongoing seismic risk in the region.

On October 4, 2024, a magnitude 1.6 earthquake was recorded approximately 37 miles east of Chenega Bay, Alaska. The seismic event occurred at 05:14:30 AKDT (13:14:30 UTC) at a depth of 12.1 miles (19 km). Although this event has not yet undergone formal review by a seismologist, it is noteworthy within the context of seismic activity in the region. Geographically, the earthquake’s location is significant as it lies in proximity to various notable landmarks: it is situated 46 miles south of Tatitlek, 47 miles southwest of Cordova, and further exceeds vast distances to other locations such as Valdez and Anchorage. The coordinates of this earthquake are approximately 60.2128°N and 146.9586°W. The southern Alaska region is notable for its tectonic complexity, with the area’s seismicity attributed to both megathrust faults and crustal seismicity. The tectonic setting of Southern Alaska is characterized primarily by the subduction of the Pacific Plate beneath the North American Plate along the convergent boundaries of the region. The strongest seismic events, including the magnitude 9.2 Great Alaska Earthquake of 1964, can be traced to this megathrust zone. Moreover, the Wadati-Benioff Zone, which accounts for intermediate-depth seismicity, stretches from the Aleutian Arc through to the northern foothills of the Alaska Range, marking the descent of the subducting plate towards the mantle. Events such as the M7.1 earthquakes in Iniskin and Anchorage further illustrate the region’s susceptibility to significant seismic activity, causing considerable ground shaking and infrastructure damage. Additionally, crustal seismicity in this area can be attributed to distinct geological formations, including the numerous faults and folds in the Cook Inlet basin. The Castle Mountain Fault and the diffuse zone of seismicity represent critical areas where seismic events have historically occurred, contributing to the overall understanding of earthquake mechanisms in Southcentral Alaska. Notably, significant earthquakes, such as the 1933 M6.9 earthquake which damaged Anchorage, are reminders of this area’s geological volatility.

Understanding the tectonic setting of Southern Alaska is essential for grasping the complexities of seismic activity in this region. The landscape is shaped by the interaction between different tectonic plates, primarily the Pacific and North American plates, which creates a fault system marked by the risk of significant earthquakes. Historical events provide context for the ongoing seismic risk, emphasizing the importance of monitoring and understanding these dynamics.

In summary, the magnitude 1.6 earthquake near Chenega Bay on October 4, 2024, highlights the continuous seismic activity prevalent in Southern Alaska. This region operates within a complex tectonic framework where numerous fault systems interact, underlining the necessity for ongoing studies and preparedness strategies in the face of potential large-scale seismic events.

Original Source: earthquake.alaska.edu