Five major earthquakes since the Late Classic Maya Period on the Motagua Fault in Guatemala

In 1976, the Motagua Fault along the North American-Caribbean plate boundary ruptured in a devastating M 7.5 earthquake. Despite its considerable scientific importance and its potential for catastrophic societal impact, very little is known about the seismic history of this major fault. Here, we show direct on-fault paleoseismic evidence for five ground-rupturing earthquakes on the Motagua Fault in the last 1,300 years that led to cultural and architectural adaptations. Radiocarbon ages of fault scarp-derived colluvial wedges, along with damage and repair at Maya and Colonial sites, provide constraints for three earthquakes during the 8th–13th centuries and two during the 18th-20th centuries, separated by a six-century interval of seismic quiescence. The research presented here provides new insight into the seismic character of the Motagua Fault and illustrates that earthquake recurrence on the fault is variable, allowing for improved estimation of current and future seismic risk in Guatemala. The Motagua Fault in Guatemala, part of the North American-Caribbean plate boundary, ruptured the ground surface on five separate occasions over the past 1300 years, according to direct observations from excavations coupled with radiocarbon dating