2010 Haiti earthquake

===Aftershocks===
[[File:Haiti 2010 history.svg|thumb|History of the main shock and aftershocks with magnitudes larger than 4.0, data from USGS<ref name="USGS database" />]]

The U.S. Geological Survey recorded eight [[aftershock]]s in the two hours after the main earthquake, with magnitudes between 4.3 and 5.9.<ref name="USGS database"/> Within the first nine hours, 32 aftershocks of magnitude 4.2 or greater were recorded, 12 of which measured magnitude 5.0 or greater; in addition, on 24 January, the US Geological Survey reported that there had been 52 aftershocks measuring 4.5 or greater since the main quake.<ref name="USGS database"/>

On 20 January, at 06:03 local time (11:03 [[UTC]]), the strongest aftershock since the earthquake,<ref name="CNN aftershock" /> measuring magnitude 5.9&nbsp;M<sub>w</sub>, struck Haiti.<ref name="NYT aftershock" /> USGS reported its epicenter was about {{convert|56|km|mi|abbr=on}} WSW of Port-au-Prince,<ref name="USGS database"/> which would place it almost exactly under the coastal town of [[Petit-Goâve]]. A UN representative reported that the aftershock collapsed seven buildings in the town.<ref name="AP aftershock" /> According to staff of the [[International Committee of the Red Cross]], which had reached Petit-Goâve for the first time the day before the aftershock, the town was estimated to have lost 15% of its buildings, and was suffering the same shortages of supplies and medical care as the capital.<ref>[http://www.icrc.org/web/eng/siteeng0.nsf/html/haiti-earthquake-update-190110 Haiti earthquake: reaching victims outside the capital] {{Webarchive|url=https://web.archive.org/web/20210502113711/https://www.icrc.org/en |date=2 May 2021 }}, International Committee of the Red Cross, 19 January 2010</ref> Workers from the charity [[Save the Children]] reported hearing "already weakened structures collapsing" in Port-au-Prince,<ref name="CNN aftershock"/> but most sources reported no further significant damage to infrastructure in the city. Further casualties are thought to have been minimal since people had been sleeping in the open.<ref name="AP aftershock"/> There are concerns that the main earthquake could be the beginning of a new long-term sequence: "the whole region is fearful"; historical accounts, although not precise, suggest that there has been a sequence of quakes progressing westwards along the fault, starting with an earthquake in the Dominican Republic in 1751.<ref name="future" />