The December 18, 2023, M5.9 earthquake in north-central China occurred as a result of reverse faulting at shallow depth. The earthquake occurred on either a north-striking, steeply dipping, reverse fault or a south-southeast striking, shallowing-dipping, reverse fault. The region where the December 18th earthquake occurred is an intraplate (i.e., not at a plate boundary) region located on the northern margin of the Tibetan Plateau. The Tibetan Plateau is a high topographic region north of the Himalaya Mountains that developed in response to ongoing collision between the India and Eurasia plates.
The Tibetan Plateau is tectonically active, and earthquakes are common throughout the region. Within 250 kilometers of today's event, 23 M5.5 and larger earthquakes have occurred since 1900. The largest of these is a M7.7 earthquake in May 1927, to the north that resulted in roughly 40,000 fatalities. The 1927 earthquake resulted in extreme damage in the Gulan-Wuwei area and resulted in damaging landslides. In April 1990, a M6.5 earthquake, immediately preceded by a M6.3 foreshock and followed by a M6.3 aftershock, led to at least 126 fatalities and extensive shaking damage and landslides. Earthquake-related losses in China are common, even for moderate magnitude earthquakes, owing to the proximity of large population centers to shaking, the prevalence of structures that are vulnerable to earthquake shaking, and the occurrence of landslides in steep topography.
The M 5.9 earthquake was likely caused by tectonic activity along the boundaries of the Eurasian and Indian tectonic plates. These plates interact in this region, leading to stress accumulation and eventual release in the form of earthquakes.
The earthquake occurred on [insert specific date and time here], which is crucial for understanding its impact and the response efforts that followed.
The earthquake occurred at a depth of approximately 37 kilometers, which is considered to be a relatively shallow depth for an earthquake of this magnitude, potentially increasing its surface impact.
The effects of the earthquake included shaking felt by residents, potential damage to buildings and infrastructure, and possible disruption of services. The severity of these effects can vary based on proximity to the epicenter and local building codes.
No tsunami warning was issued following the M 5.9 earthquake, as it occurred inland and did not meet the criteria for generating a tsunami. Tsunami warnings are typically relevant for undersea earthquakes.