Between a Rock and a Hard Place

Science Snap (#34) – Kick ’em Jenny

Kick ’em Jenny is a submarine volcano located 8km to the north of the Caribbean island of Grenada. It lies close to the small, uninhabited volcanic islands of Ronde, Diamond, Ill Caille and Les Tantes, though no physical evidence of the volcano is evident from land.


Location of Kick ’em Jenny. Credit: USGS

At least twelve recorded eruptions have occurred since Kick ’em Jenny’s discovery in 1939 (the last in 2001), and it is currently the most active volcano in the Lesser Antilles arc. Underwater surveys conducted over the last 50 years have demonstrated that the summit lies at a depth of between 150 – 250m below sea level, with the height varying as the volcano goes through cycles of dome growth and collapse.

A submarine expedition in 2003 revealed that the volcano is actively degassing, presenting a significant hazard for shipping activity in the area. Any eruptive episode introducing a high concentration of gas within a water column will result in a localised area of reduced density, manifest for any passing vessels as negative buoyancy (i.e., sinking!).

“One of Grenada’s worst maritime tragedies may have resulted from just this phenomenon. On the 5th August 1944, the wooden schooner Island Queen, with over 60 people on board, disappeared between Grenada and St Vincent. At the time it was thought that a German or Allied submarine had torpedoed the boat. These theories, however, cannot easily explain the total lack of debris after the boat’s disappearance.” Source: UWI Seismic Research Centre

For this reason, a 1.5km maritime exclusion zone is currently in place above the volcano.

The origin of the name ‘Kick ’em Jenny’ is disputed; possibilities include a reference to the rough seas often encountered in the area, or a colloquial translation of the French cay que gêne [the troublesome cay]. Kick ’em Jenny has stiff competition for the world’s best volcano name, however, as a smaller nearby crater discovered by recent bathymetric surveys has been named Kick ’em Jack.

Kick 'em Jenny

Morphology of Kick ’em Jenny, as revealed by a multi-beam survey carried out by the NOAA in 2002. The sub-circular summit crater is about ~ 300 m in diameter. Photo credit: NOAA

Charly completed a PhD in experimental petrology. She used to make pretend volcanoes; now she works in renewable energy. Charly tweets at @C_Stamper.