Volcano World

March 18, 2003

On March 15, a remotely operated submarine captured images of the crater floor. Aside from the smooth, ash-covered floor, an ellipical inner crater was visible. Fumaroles were also observed emitting cold and hot gas bubbles.

This information was summarized from the GVP/USGS Weekly Volcanic Activity Report

Kick-'em-Jenny is a submarine volcano located 6 miles (10 km) north of the island of Grenada. It is the southern-most active volcano in the Lesser Antilles volcanic arc and the only active submarine volcano in the arc.

Kick-'em-Jenny and the other volcanoes in the arc are associated with a subduction zone. The subduction zone is formed by an oceanic plate created at the Mid-Atlantic Ridge as it is pushed under the Caribbean Plate.

This figure is a geologic map of Kick-'em-Jenny by Sigurdsson and Shepherd (1974). Calle Island is made of two youthful craters and lava flows. Kick-'em-Jenny has erupted 10 times since 1939 with the most recent eruption in 1990. The 1939 eruption sent a black cloud up to 885 feet (270 m) above sea level. During the 1965 eruption, earthquakes of intensity V were felt on Isla de Ronde.

During the 1974 eruption, the sea above the volcano was boiling turbulently and spouting steam. Most of the eruptions were detected by submarine hydrophones. The hydrophones detect shock waves from explosive eruptions as they travel through the water. Using data from several hydrophones, volcanologists can determine where an active submarine volcano is located and when it started erupting.

There is no indication that eruptions at Kick-'em-Jenny are hazardous.

Kick-'em-Jenny has a basal diameter of about 3 miles (5 km) and rises about 4,300 feet (1,300 m) above the sea floor. Oceanographic surveys found a crater at the summit of the volcano and retrieved samples of fresh olivine basalt pyroclasts.

-Steve Mattox

Sources of Information:

Sigurdsson, H., and Sparks, R.S.J., 1979, An active submarine volcano [Kick-'em-Jenny]: Natural History, v. 88, p. 38-43.

Sigurdsson, H., and Shepherd, J.B., 1974, Amphibole-bearing basalts from the submarine volcano Kick-'em-Jenny in the Lesser Antilles Island Arc: Bull. Volc., v. 38, p. 891-910.

Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.