Seismic activity at Kick ’em Jenny submarine volcano, Grenada

The University of the West Indies Seismic Research Center (UWI SRC) has reported a return to normal seismic activity levels at the Kick ’em Jenny submarine volcano in Grenada as of early February 11, 2024, following increased activity since February 9. The National Disaster Management Agency (NaDMA) Grenada maintains a Yellow alert level, advising continued adherence to the 1.5 km (0.9 miles) marine exclusion zone.

On Monday, February 12, 2024, the National Disaster Management Agency (NaDMA) of Grenada issued a statement regarding the seismic activity at the Kick ’em Jenny submarine volcano. According to the University of the West Indies Seismic Research Center (UWI SRC), there was a notable increase in seismic activity starting at 23:14 LT on Friday, February 9, 2024. This heightened activity prompted concerns of potential escalation.

However, by 03:00 LT on Sunday, February 11, the situation had significantly improved, with the seismic activity decreasing in both magnitude and frequency, eventually returning to what is considered normal levels.

The count of events up to that time was 3 400, with the largest measuring M3.3 on February 10.

Despite this positive development, the UWI SRC has cautioned that the volcano’s activity may still fluctuate, potentially increasing, decreasing, or stabilizing at current readings.

The volcano is being continuously monitored by four fully functional seismic stations located in the north of Grenada.

INaDMA Grenada has decided to maintain the alert level for Kick ’em-Jenny at Yellow. This level of alert signifies a phase where there is a need for preparedness for a range of activity levels. It also mandates that all marine interests adhere to the established exclusion zone of 1.5 km (0.9 miles) around the volcano to ensure safety and minimize the risk of any potential hazards that could arise from sudden changes in volcanic activity.

Kick ’em Jenny, located 8 km (5 miles) off the northern shore of Grenada, is an active submarine volcano that rises 1 300 m (approximately 4 265 feet) from the sea floor.

Investigations have uncovered a significant arcuate collapse structure responsible for a submarine debris avalanche extending more than 15 km (about 9.3 miles) westward. Additionally, bathymetric surveys identified a nearby submarine cone, Kick ’em Jack, and several submarine lava domes to the south, suggesting these features, along with subaerial tuff rings and lava flows on Ile de Caille and neighboring islands, might form part of a large volcanic complex.

Documented eruptions have occurred frequently since 1939, mainly identified through acoustic signals. The 1939 eruption, which sent a cloud 275 m (around 902 feet) above the sea, visible to many in northern Grenada, was the first recorded activity. Eruptions have ranged from explosive to the quiet extrusion of lava flows and domes, with deep rumbling noises sometimes heard onshore. Recent activities have also altered the summit crater’s shape.

The last eruptive episode at this volcano took place on March 29, 2017 (VEI 0).

References:

¹ MaDMA Media Release for Kick ’em Jenny #3 February 12, 2024

² Kick ’em Jenny – Geological summary – GVP

Featured image credit: Copernicus EU/Sentinel-2, The Watchers. Acquired on February 12, 2024.