Major earthquake in Haiti

Location: 18.352N,  73.480W (12.1 km (~7.5 mi) NE of Saint-Louis du Sud, Haiti)

Magnitude:  7.2

Depth: 10 km (6 miles) beneath earth’s surface

Universal Time (UTC):  14 Aug 2021  12:29:09

Time near the Epicenter: 14 Aug 2021  08:29:09 AM

 Note that the earthquake occurred just 31 minutes after another major event, a M6.9 earthquake offshore Alaska, so the two seismograms are merged on this record.

USGS Earthquake Site

History of the Station

The station was established in collaboration with St. Louis University’s seismology laboratory—a regional center led by Prof. Otto Nuttli, one of the pioneers of midcontinent seismology research. The IU seismograph was one of about five state-of-the-art seismograph stations set up to the standards of the Worldwide Seismograph Station Network (WWSSN) and provided important constraints on midcontinent seismic activity for several decades. Originally operated near the IU golf course, it was relocated in the early 1960s into a special seismic vault that was built into the newly constructed Geology Building. Until the late 1980s, it operated using a photographic recording system. At that time, it was converted to a less cumbersome pen/ink recording system, more suitable to education and outreach uses.

In about 1995, the analog system was updated with a broadband digital recording system by the St. Louis University team. The IU seismograph station has been operating continuously since the early 1960s. The IU collection contains analog seismograms for ~55 years, consisting of approximately 120,000 individual paper seismograms.

For the last 20 years, data are collected digitally, and archived by the IRIS (Incorporated Research Institutions for Seismology) consortium.