2009 Swan Islands earthquake

2009 Swan Islands earthquake

Belmopan Tegucigalpa
UTC time	2009-05-28 08:24:46
ISC event	12867661
USGS-ANSS	ComCat
Local date	May 28, 2009 (2009-05-28)
Local time	02:24
Magnitude	7.3 Mw
Depth	10 kilometres (6.21 mi)
Epicenter	16.73°N 86.22°W / 16.73; -86.22
Fault	Swan Islands Transform Fault
Type	Strike-slip
Areas affected	Honduras Guatemala Belize
Max. intensity	MMI VII (Very strong)
Tsunami	4 m (13 ft)[1]
Casualties	7 killed, 40 injured

The 2009 Swan Islands earthquake occurred on May 28 at 02:24:45 AM local time with a moment magnitude of 7.3 and a maximum Mercalli intensity of VII (Very strong). The epicenter was located in the Caribbean Sea, 64 kilometres (40 mi) northeast of the island of Roatán, 19 miles northeast of Port Royal, Isla de Bahias, 15 miles northwest of Isla Barbaretta, and 130 kilometres (81 mi) north-northeast of La Ceiba.^[2] Three aftershocks followed the earthquake within magnitude 4 range.^[3]

Earthquake

The earthquake occurred at a depth of around 10 kilometres (6.2 mi) on a transform fault zone known as the Swan Islands Transform Fault on the southern margin of the Cayman Trough. It was a result of left-lateral strike-slip faulting. The Swan Island Transform Fault forms part of the tectonic boundary between the North American plate and the Caribbean plate, and continues onshore as the Motagua Fault and the Chixoy-Polochic Fault.

The 30-second offshore quake was felt in Guatemala, El Salvador, Belize, and as far as Cancún in Mexico. It was also felt in parts of Nicaragua, Costa Rica, Panama, Colombia, Cuba, Jamaica, and the Cayman Islands.^[2][4][5]

Analysis of geodetic and seismic data indicated that up to 1 meter of slip occurred across a 250-km-long fault rupture. Although the epicenter was located far off the coast of Central America, the long rupture contributed to severe damage in Honduras. The earthquake ruptured a segment of plate boundary immediately east of the 1976 earthquake rupture on the Motagua Fault.^[6]

Tsunami

A tsunami was observed with heights of 4 m (13 ft) in Motagua River, Guatemala.^[1]

Damage

The damaged Democracy Bridge in El Progreso

The earthquake caused at least seven fatalities, 40 injuries, and more than 130 collapsed or damaged buildings across northern Honduras.^[2] Two important bridges and a number of levees and port terminals were also seriously damaged.^[7] In the Guatemalan department of Izabal, 35 buildings were destroyed and 80 were damaged. In Belize, at least 5 buildings were also destroyed and 25 were damaged. In Roatan, one home was damaged and one injury occurred.^[2][8] The earthquake caused an estimated $37 million worth of damage, and electricity, Internet and telephone connections were cut throughout the majority of Honduras.^[9]

A tsunami watch was put into effect by the Pacific Tsunami Warning Center for Honduras, Guatemala, and Belize and was discontinued 90 minutes after the earthquake occurred.^[4]

See also

• List of earthquakes in 2009
• 2018 Swan Islands earthquake

References

1. Tsunami Event: SWAN ISLANDS, HONDURAS, NGDC
2. "Magnitude 7.3 – OFFSHORE HONDURAS". United States Geological Survey. Archived from the original on 31 May 2009. Retrieved 28 May 2009.
3. "7.3-Magnitude Quake off the Honduras Coast : Natural Hazards". NASA Earth Observatory. 2009-05-28. Retrieved 2016-02-09.
4. "Major quake strikes off Honduras". BBC News. 2009-05-28. Archived from the original on 23 January 2010. Retrieved 2010-01-01.
5. Cuevas, Freddy (2009-05-28). "7.1 earthquake topples homes, kills 6 in Honduras". Miami Herald. Retrieved 2009-05-30.
6. Shannon E. Graham; Charles DeMets; Heather R. DeShon; Robert Rogers; Manuel Rodriguez Maradiaga; Wilfried Strauch; Klaus Wiese; Douglas Hernandez (2012). "GPS and seismic constraints on the M = 7.3 2009 Swan Islands earthquake: implications for stress changes along the Motagua fault and other nearby faults". Geophysical Journal International. 190 (3): 1625–1639. Bibcode:2012GeoJI.190.1625G. doi:10.1111/j.1365-246X.2012.05560.x.
7. Belarbi, A., Luna, R., Applegate, K., Calderon, H., Rivera, O., Lopez, L.A. and Rodriguez, R., 2009. The M7.3 Honduras Earthquake of May 28, 2009, EERI Special Earthquake Report, 1–4
8. La Tribuna. "Seísmo destruyó 35 viviendas y dañó otras 80 en el Caribe guatemalteco". Retrieved 2009-05-29. ^{[permanent dead link‍]}
9. "7.1 Earthquake Hits Honduras, Belize". Huffington Post. Retrieved 2016-02-15.

Further reading

• Graham, S. E.; Demets, C.; Deshon, H. R.; Rogers, R.; Maradiaga, M. Rodriguez; Strauch, W.; Wiese, K.; Hernandez, D. (2012), "GPS and seismic constraints on the M = 7.3 2009 Swan Islands earthquake: Implications for stress changes along the Motagua fault and other nearby faults", Geophysical Journal International, 190 (3): 1625–1639, Bibcode:2012GeoJI.190.1625G, doi:10.1111/j.1365-246X.2012.05560.x

External links

• The Magnitude 7.3 Honduras Earthquake May 28, 2009 – ExploringEarth
• "Poster of the Honduras Earthquake of 28 May 2009 – Magnitude 7.3". United States Geological Survey. Archived from the original on 5 March 2016. Retrieved 2016-02-29.
• The International Seismological Centre has a bibliography and/or authoritative data for this event.