M 8.5 - Northeast of Grand-Terre, Guadeloupe

At least 1,500 people were killed (with some estimates being as high as 5,000 killed), mostly in Guadeloupe. At many places the quake was estimated to have lasted about 3 minutes, with some estimates saying it lasted as long as 5 minutes. Damage occurred on many islands and a small tsunami was observed on Antigua. The earthquake was felt throughout the Windward and Leeward Islands. It was also felt in British Guiana (now Guyana), Surinam (now spelled Suriname) and Venezuela, in Puerto Rico and Bermuda, and at various places along the East Coast of the United States from Florida to New York. Magnitude estimates for this earthquake range from about 7.5 to 8.5, and the maximum observed Modified Mercalli Intensity (MMI) is IX.

In Guadeloupe, the earthquake destroyed the city of Pointe-à-Pitre and killed more than 1,500 people. Mud fountains up to 1.5 m high were observed across all of Grande-Terre and along the eastern coast of Basse-Terre. New springs appeared and others dried up or flow rates changed significantly. The water level changed in some wells on Grande-Terre. The earthquake also induced large cliff collapses along the eastern coast of Guadeloupe and several landslides were reported on volcanic domes. It was reported that the Pointe-à-Pitre wharfs subsided by 30 cm. Small islands also subsided in the bay of Pointe-à-Pitre. By contrast, the eastern coast of Grande-Terre was apparently uplifted by some tens of centimeters.

The earthquake was followed by many aftershocks that were felt in Guadeloupe with intensities ranging between III and VII. The largest aftershock occurred on 11 May 1843.

The mainshock was probably a megathrust earthquake, rupturing the deeper part of the North America-Caribbean plate interface between Grande-Terre and Antigua. There are conflicting studies concerning the extent of the intensity IX effects on the various islands, which, along with the relatively small tsunami that occurred, has resulted in large differences in the estimated magnitude for the earthquake, from a low of about 7.5-8.0 up to about 8.0-8.5.

Abridged from Tectonic context of moderate to large historical earthquakes in the Lesser Antilles and mechanical coupling with volcanoes, by Nathalie Feuillet, François Beauducel and Paul Tapponier (2011), Journal of Geophysical Research, Solid Earth, 116, B10308.

The earthquake struck Guadeloupe at 10:30 AM. In Pointe-à-Pitre, all masonry structures were destroyed. An eyewitness described columns of water one hundred feet [30 m] high and several feet thick ejected from fissures in the ground. A fire following the earthquake destroyed the remaining wooden buildings. One third of the population of the town was killed; variously estimated as four to six thousand people. Elsewhere in the island all masonry structures were destroyed or severely damaged. Maximum observed Modified Mercalli Intensity (MMI) was IX.

The earthquake struck Antigua at 10:40 AM. At Saint John's and in much of the island, all masonry structures were destroyed or severely damaged. Many houses were left with their outer masonry walls collapsed and the inner walls supporting the roof. Wooden houses remained standing. Alluvial ground was fissured and sulfurous water was ejected. Landslides were common on hill slopes. At English Harbour [southeastern Antigua] the wharf, which was built on landfill, sank and afterwards had an undulating appearance "like waves on the sea". A cloud of dust hung over the island for several minutes. After the earthquake the sea rose four feet [1.2 m] but sank again immediately, remaining calm throughout [i.e. a tsunami, with 1.2 m runup]. The number of people killed on Antigua was estimated to be between twelve and forty and the total damage in the island including the loss of the sugar crop was estimated at £2 million [equivalent to approximately £265 million in 2021¹ or about US$357 million at the 31 Dec 2021 conversion rate²]. Maximum observed MMI was IX.

On Montserrat, all masonry structures including public buildings, private houses and sugar mills were severely damaged and unusable. Large landslips occurred on hill slopes. Six people were killed. A pall of dust hung over the island and was seen from Antigua. Maximum observed MMI was IX.

On Nevis, the Court House in Charlestown was destroyed and the Custom House was partly destroyed. All masonry houses were severely damaged, and only wooden buildings remained habitable. Only two sugar mills on the island were capable of working. Large landslips occurred on Nevis Peak. Damage in Charlestown was estimated at £50,000 [equivalent to approximately £6.6 million in 2021¹ or about US$8.9 million at the 31 Dec 2021 conversion rate²]. No one was killed. Maximum observed MMI was IX.

On Saint Christopher (St. Kitts), three buildings partially collapsed at Basseterre. All stone buildings were damaged, many needing to be rebuilt. Sugar mills and stone churches were severely damaged throughout the island. No people were killed. Maximum observed MMI was IX.

On Dominica, one person was killed. At Londonderry and Melville Hall in the northern part of the island, the sugar works and other stone buildings were destroyed. At Melville Hall the riverbed sank by a few inches and the river was diverted twenty feet [about 6 m] to the south. Maximum observed MMI here was IX. At Roseau, the walls of most masonry buildings were cracked, some severely. Several old walls and chimneys were thrown down. The maximum observed MMI here and in the southern part of the island was VIII.

On Saint Barthélemy, Saint Martin and Sint Eustatius, estate and stone buildings were damaged. No people were killed on these islands. Maximum observed MMI was VIII for each of these islands.

The quake struck Saint Lucia at 10:28 AM. At Castries, a church, the Custom House, the jail and other masonry buildings were cracked, but there was no severe damage. Maximum observed MMI was VII.

The earthquake was described as long and violent at Saint Pierre, Martinique. Maximum observed MMI on this island was VII.

A severe shock (MMI V) was felt on Grenada. In the Virgin Islands, the quake struck Tortola (MMI V) and Saint Thomas³ (MMI IV) at 10:30 AM. There was no damage on either island. A slight shock was felt on Trinidad, and bottles shook on shelves at Georgetown, British Guiana [now Guyana].

Abridged from An Earthquake Catalogue for the Eastern Caribbean 1530-1960, by G.R. Robson, Bulletin of the Seismological Society of America, 54(2), 785-832, April 1964.

A ship at sea about 160 miles [about 255 km] due east of Antigua was "stopped in her way" by a severe earthquake shock, which lasted about 4 minutes.
Barbados was "shaken severely but no damage done." Many people ran from buildings on that island, and the duration of the shaking was reported to be 1½ to 2 minutes.
In British Guiana [now Guyana], "every house was shaken" and some chimneys fell.

On Saint Thomas³, Virgin Islands, many people ran into the streets. Shaking lasted about 2 minutes.
An anonymous report in the Archivo Histórico Nacional [National History Archives] in Madrid, Spain, stated that customs houses were damaged at Guayama, Mayagüez and Naguabo, Puerto Rico³.

Abridged from Catalog of felt earthquakes for Puerto Rico and neighboring islands 1493-1899, with additional information for some 20th century earthquakes, by William McCann, Lawrence Feldman and Maribel McCann (2011), Revista Geofísica, Instituto Panamericano de Geografía e Historia, Mexico, no.62, p.141-293.

The earthquake was felt by many people in Bermuda. It was also felt at Caracas, Venezuela, and was slightly felt in Surinam [now spelled Suriname].
The Baltimore Sun reported that the earthquake lasted 1 minute at San Juan, Puerto Rico³, and the Pennsylvania Inquirer reported that it was felt on Saint Croix³, Virgin Islands.

In the United States, the earthquake was felt most strongly at Newbern [now known as New Bern], and at Wilmington, North Carolina (MMI III-IV). The quake struck Newbern at 9:55 AM. At least one person ran from their house at Wilmington, and the Southern Patriot reported that some glassware was knocked down at Swift Creek, about 14 miles [22 km] from Newbern. The quake was also felt in central Florida and at Washington, DC; Savannah, Georgia; Annapolis and Baltimore, Maryland; New York, New York; Greensboro and Raleigh, North Carolina; Charleston and Columbia, South Carolina; and Richmond, Virginia.

Abridged from Missing great earthquakes, by Susan E. Hough (2013), Journal of Geophysical Research: Solid Earth, 118, 1098-1108.

A great earthquake that caused considerable damage in Guadeloupe appears to have been felt in the eastern part of the United States, especially at Washington, D.C. It was reported felt in New York, Pennsylvania, Ohio, Maryland, Virginia (including West Virginia), and in several towns in North Carolina. It is possible [but unlikely] there were two separate earthquakes. It was probably felt in eastern Puerto Rico, and was felt with Modified Mercalli Intensity (MMI) IV in the Virgin Islands.

Abridged from Earthquake History of the United States, by Jerry L. Coffman, Carl A. von Hake and Carl W. Stover, National Oceanic and Atmospheric Administration and U.S. Geological Survey, Publication 41-1, Revised Edition (Through 1970), Reprinted 1982 with Supplement (1971-1980), United States Government Printing Office, Washington: 1982.

¹Based on United Kingdom Composite Price Index and calculated in "U.K. Inflation Calculator", Official Inflation Data, Alioth Finance (https://www.officialdata.org/UK-inflation), retrieved 11 Mar 2022
²Calculated using "Currency Converter" provided by OANDA Business Information and Services, Inc. (https://www.oanda.com/currency-converter/en/).
³At the time of this earthquake, Saint Thomas and Saint Croix belonged to Denmark, and Puerto Rico belonged to Spain.