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Alert level: YELLOW. A 5km exclusion zone is currently around the summit of the
volcano. |
What is Kick 'em Jenny?
Kick 'em Jenny is a submarine volcano located 8km north of Grenada (12.18°N, 61.38°W).
The volcano is about 1300m high and 300m wide at its summit, which is currently thought
to
be about 180m below the surface of the sea. As far as we know,
Kick 'em Jenny is the only 'live' (likely to erupt again) submarine
volcano in the Eastern Caribbean. It is also the most frequently
active volcano in the region, erupting at least 13 times since it
was discovered in 1939. The most recent eruption of Kick 'em Jenny
occurred in July 2015. For details of that and previous eruptions go to
news archives. The volcano is currently at
Alert Level YELLOW.
The YELLOW alert level means that vessels should observe a 1.5 km exclusion zone. However, as a precautionary measure, the marine community is advised to continue observing the 5 km exclusion zone.
Kick 'em Jenny is also a modern day demonstration of how the volcanic islands
in this region were formed. With each submarine eruption deposits of volcanic
material accumulate around the summit. All of the volcanic islands of the
Lesser Antilles began as submarine volcanoes.
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How deep is Kick 'em Jenny?
Between the 1960's and the late 1970's the depth to the summit of the volcano was
approximately 180-190m. In the 1970's and early 1980's the depth to the summit of
the volcano decreased to approximately 150m, reflecting the growth of a dome within
the crater. This dome was destroyed during eruptions in the late 1980's and a survey
conducted by the U.S.-based National Oceanic and Atmospheric Administration (NOAA)
in March, 2002 revealed that the summit is currently 180m below the surface of the
sea.
SeaBeam image of Kick 'em Jenny showing new craters and domes (March, 2003).
During a research cruise in March 2003 scientists discovered three craters (C1, C2 and Kick 'em Jack) and two domes (D1 and D2) near Kick 'em Jenny. Further investigations are needed to confirm whether these are separate 'live' volcanoes. |
Until recently it was thought that Kick 'em Jenny had grown 46m (from 236m to 190m
below sea level) between the surveys of 1962 and 1966. However, data collected from
the two most recent cruises (March 2002 and March 2003) and a careful re-examination
of data collected on even earlier cruises make it clear that the crater rim of Kick
'em Jenny has remained at the same depth below the surface (180-190m, within measurement
uncertainty) since at least 1966. The major sequence of changes over the past forty
years has been that a dome grew in the crater between 1976 and 1978. This dome collapsed
in either 1988 or 1990 and there is now no trace of it left. There is in fact a
new interior crater about 30 metres deep on the site where the dome used to be so
it is more accurate to say that the active vent area of Kick 'em Jenny has in fact
become deeper.
Kick 'em Jenny has, therefore, NOT grown closer to the surface
between 1962-2003.
Where is Kick 'em Jenny?
Kick 'em Jenny is located approximately 8km north of Grenada (12.18 degrees North,
61.38 degrees West). This location is in the southern part of the Grenadine Islands
which are themselves in the southern part of the Lesser Antilles island arc (see
Map 1 below). The volcano should not be confused with the nearby Diamond Rock, which
is also called 'Kick 'em Jenny' on some charts.
On land the location is clearly visible from northern Grenada. From Sauteurs look
towards the Île de Ronde. West - i.e. to the left - of the Île de Ronde is a small
group of rocks called The Sisters. Kick 'em Jenny is 1.6 nautical miles (about 3
km) due west of the Sisters or about as far west of the Sisters as the Sisters are
of the Île de Ronde. Marine vessel operators may
click here for additional yachting
information.
Map 1. Location of Kick 'em Jenny in the southern Grenadines.
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Map 2. Kick 'em Jenny is 8km north of Grenada.
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SeaBeam Image
The image below is a SeaBeam image of Kick 'em Jenny constructed from
measurements taken from the NOAA Research Vessel Ronald H. Brown between 12th-21st
March, 2003. The crater of Kick 'em Jenny is clearly visible just to the right of
the centre of the image on top of a symmetrical cone. The crater is almost perfectly
circular and has a diameter of approximately 350m. The centre of the crater is at
12.3004 degrees North 61.6378 degrees West. The highest point on the crater rim
is at 61.6398 degrees West 12.3004 degrees North and is 180m below sea level.
The dome, which was first noticed in 1978 and almost completely filled the crater
up to at least 1985 has now disappeared completely. The depth from the highest point
of the crater rim to the lowest point of the crater floor is about 80m. The crater
is breached to the northeast and contains an interior crater about 30m deep. The
summit sits within a much bigger horseshoe-shaped depression which extends at least
20km to the west of Kick 'em Jenny and widens from about 5km to 10km. The depression
contains a sequence of debris-flow deposits.
Complete interpretation of the data is still in progress. The interpretations here
are preliminary and should not be quoted or reproduced elsewhere
(See Disclaimer).
SeaBeam image of Kick 'em Jenny. March, 2003
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