Geology topics

Research about Lesser Antilles

Source-linked reports with geographic coverage including Lesser Antilles.

4 recordsLinked to original sources

USGS2025

Earthquake recurrence estimates for northern Caribbean faults from combinatorial optimization

We use combinatorial optimization to find the optimal spatial distribution of random samples of earthquakes (≥6.5) that minimize the misfit in target slip rates for all faults in the northeast Caribbean, and we derive magnitude-frequency relationships with uncertainties for these faults. Slip rates for many faults are derived from GPS block models, not direct measurements, because of their underwater locations. Predicted recurrence rates for eastern Hispaniola and Puerto Rico Trench faults are 220-450 yr for M7 and 3-5 kyr for M8, with maximum feasible magnitude of M8.2. The most frequent earthquakes with magnitudes ≥7.0 are predicted on the large upper plate strike-slip faults, Enriquillo (EF) and Septentrional Fault, commensurate with the historical record. Calais et al. (2023) suggested that shortening in western Hispaniola is accommodated on the offshore Jérémie and onshore Malpasse faults north and south of EF, instead of on terrestrial faults in western Hispaniola and EF. Because of our system-modeling approach, such a configuration predicts less frequent earthquakes on EF and on western Hispaniola and Muertos convergent zones. Recurrence times of a few 100s yr for M6.7 earthquakes is predicted on the submerged faults in Mona Passage, and infrequent M>7 earthquakes are predicted on the Virgin Islands faults.

Lesser Antilles↗

USGS2013

Quantifying potential earthquake and tsunami hazard in the Lesser Antilles subduction zone of the Caribbean region

In this study, we quantify the seismic and tsunami hazard in the Lesser Antilles subduction zone, focusing on the plate interface offshore of Guadeloupe. We compare potential strain accumulated via GPS-derived plate motions to strain release due to earthquakes that have occurred over the past 110 yr, and compute the resulting moment deficit. Our results suggest that enough strain is currently stored in the seismogenic zone of the Lesser Antilles subduction arc in the region of Guadeloupe to cause a large and damaging earthquake of magnitude M w ∼ 8.2 ± 0.4. We model several scenario earthquakes over this magnitude range, using a variety of earthquake magnitudes and rupture areas, and utilizing the USGS ShakeMap and PAGER software packages. Strong ground shaking during the earthquake will likely cause loss of life and damage estimated to be in the range of several tens to several hundreds of fatalities and hundreds of millions to potentially billions of U.S. dollars of damage. In addition, such an event could produce a significant tsunami. Modelled tsunamis resulting from these scenario earthquakes predict meter-scale wave amplitudes even for events at the lower end of our magnitude range (M 7.8), and heights of over 3 m in several locations with our favoured scenario (M 8.0, partially locked interface from 15–45 km depth). In all scenarios, only short lead-times (on the order of tens of minutes) would be possible in the Caribbean before the arrival of damaging waves.

Lesser Antilles↗

USGS1971

Isotopic composition of strontium in three basalt-andesite centers along the Lesser Antilles arc

Si 87 /Sr 86 ratios have been determined for lavas and py lastic rocks from three basalt-andesite centers along the Lesser Antilles arc—Mt. Misery on the island of St. Kitts, Soufriere on the island of St. Vincent, and Carriacou, an island of The Grenadines. The average Si 87 /Sr 86 content of these rocks is 0.7038 for Mt. Misery, 0.7041 for Soufriere, and 0.7053 for Carriacou. All the Sr 87 /Sr 86 values from each center are the same within analytical uncertainty (±0.0002). The constancy of strontium isotopic data within each center supports the hypothesis that basalts and andesites for each specific center investigated are generated from the same source — in agreement with petrographic and major- and minor-element data. Strontium isotopic compositions and elemental concentrations, particularly of strontium and nickel, indicate that this source was mantle peridotite and that the relationship between the respective basalts and andesites is probably fractional crystallization.

Contributions to Mineralogy and Petrology↗

USGS1960

Pumice and pozzolan deposits in the Lesser Antilles

Early in 1959 the International Cooperation Administration requested the U. S. Geological Survey to assign a geologist to a reconnaissance study of the pumice and pozzolan deposits of the Lesser Antilles. As a result, I made brief field examinations of all the reported deposits during the period May 25 - June 23, 1959. In company with Mr. Peter Martin-Kaye, Government Geologist, Windward Islands, headquartered at Castries, St. Lucia, I examined potential pumice and pozzolan deposits in Grenada, Dominica, St. Vincent and St. Lucia. With Dr. Percy C. Henriquez of the Technical-Economic Council, Netherlands Antilles, headquartered in Curacao, I saw those of St. Eustatius. I also visited pumice deposits on Martinique, in company with Mr. Edward T. Foster, Vice President of Meekins West Indies Company of Hollywood, Fla. Short visits were made to the islands of Antigua, Barbados, Nevis, St. Kitts, and Trinidad, partly to meet the necessities of inter-island transportation and partly to get some idea of the actual or potential mineral resources of these islands.

Open-File Report↗