Natural Disaster: Understanding the Earthquake Triggered by Shifting Tectonic Plates

A significant earthquake rocked Southeast Asia recently, causing intense shaking that lasted for several minutes. Experts are investigating the reasons behind this seismic activity, its magnitude, and potential aftereffects.

The earthquake, which occurred along the Sagaing Fault, is attributed to the movement of the Indian and Eurasian tectonic plates. According to the German Research Centre for Geosciences (GFZ) in Potsdam, these plates are shifting past each other at a rate of approximately 18 millimeters per year. This gradual movement has led to the accumulation of stress in the Earth's crust, which has now been released after a remarkably quiet period of almost 70 years.

Seismologist Klaus Reicherter from the Institute of Neotectonics and Georisks at the RWTH Aachen University points out that such earthquakes are not uncommon in this region. He recalls that a catastrophic tsunami was triggered along the same tectonic boundary on December 26, 2004.

The GFZ and the U.S. Geological Survey (USGS) have assessed the earthquake's strength at 7.7 on the Richter scale, indicating a powerful event. Reicherter notes that this magnitude is significantly stronger than the most powerful earthquakes expected in Germany, which typically reach a maximum of 6.5. The energy release during this earthquake is estimated to be over twelve times greater than that of a 6.5 magnitude quake, contributing to the prolonged shaking experienced.

In terms of aftershocks, Daniel McCrum from University College Dublin reported that a significant aftershock of 6.4 occurred just twelve minutes after the initial quake, with additional minor tremors between magnitudes 4.5 and 4.6 following approximately one hour later. There remains a possibility of even more powerful aftershocks exceeding the initial quake's magnitude, as noted by Paolo Bergamo from the Swiss Seismological Service.

Reicherter warns that aftershocks could continue for an extended period, potentially lasting several months to a year. These smaller tremors can pose a risk to already weakened structures, as they may lead to further damage or collapse. The assessment of building safety in urban areas such as Bangkok and Mandalay is crucial in the aftermath of such seismic events.

The region has a historical record of seismic activity, having experienced six other earthquakes of magnitude 7 or greater since 1900 within a 250-kilometer radius of the recent event. The last significant earthquake of similar intensity occurred in January 1990, resulting in the collapse of 32 buildings. Another notable earthquake registered a magnitude of 7.9 in February 1912, south of the recent quake's epicenter.

Fabrice Cotton from the GFZ highlights the previous period of calm between 1930 and 1956 when numerous earthquakes occurred along the Sagaing Fault, followed by the current build-up of stress that ultimately led to this recent release.

Seismologists measure earthquake strength using seismographs, which capture the magnitude of ground movements. The impact of an earthquake can vary based on several factors, including its duration, the geological conditions of the area, and the construction standards of the buildings.