This devastating earthquake resulted in over 23,000 deaths and left approximately 1.5 million people homeless, occurring along the Motagua Fault at the tectonic boundary between the North American and Caribbean plates.

Interestingly, the thickest sediment deposits were found at the end of the fault rupture, contrary to the typical expectation that further lakes would have thicker deposits due to weakened seismic waves.

Obrist-Farner noted that lakes closest to the epicenter but away from the rupture path had thinner deposits, suggesting a unique directivity of the shaking.

Initial findings from the sediment cores indicate evidence of a significant earthquake in 1816, estimated to be at least magnitude 7.5.

This research aims to provide insights into the seismic risks in Guatemala, a region that has been poorly monitored due to historical events such as civil war and a lack of instrumentation.

Obrist-Farner's research team continues to analyze lake cores to enrich the understanding of seismic risks in the region.

The findings from these sediment cores may represent up to 4,000 years of lake history, providing valuable context for understanding past seismic activity.

Previous research indicated that structures 10 kilometers south of the rupture remained standing, while those directly on the fault line collapsed, highlighting the importance of the rupture's direction on damage.

Researchers analyzed sediment cores from four lakes in Guatemala to study the directional shaking caused by the magnitude 7.5 earthquake that struck on February 4, 1976.

A study led by geologists Jonathan Obrist-Farner and Jeremy Maurer from Missouri University of Science and Technology began in 2022 to investigate the paleoseismic history of Guatemala.

Field data collected by the U.S. Geological Survey after the earthquake confirmed that structures 10 kilometers south of the rupture remained intact, further illustrating the directivity of the seismic waves.

Geophysicist Jeremy Maurer emphasized the significance of the lakes' locations relative to the fault in understanding sediment deposits and the impact of the earthquake.