ISLAND PROFILES
Grenada - Kick `Em Jenny 2003 Cruise
Research Cruise Log
From the 12th-21st March, 2003 a joint team of scientists from the Seismic Research
Unit, the University of Rhode Island's Graduate School of Oceanography and the National
Oceanic and Atmospheric Administration (NOAA) conducted an oceanographic survey
and sampling of the Kick 'em Jenny submarine volcano. Professor John Shepherd, Head
of the Seismic Research Unit provided the following daily log of activities and
accompanying images for the duration of the cruise. Click on the pictures for a
larger version of the images. This project was funded by NOAA.
NOAA
University of Rhode Island
Glossary
A bathymetric survey is a series of sophisticated depth soundings over a particular
area. Depth soundings are used to measure the depth of the ocean floor beneath the
ship . Signals are transmitted from the ship down to a specific point beneath the
ship and the return speed of these signals is used to calculate the depth. Currently,
the scientists are sending thousands of signals to various points on Kick 'em Jenny.
All of these points, when put together, will be used to form a detailed bathymetric
map of the volcano like the one which was produced in March 2002.
The ROV is a remotely operated submarine which can be used to collect rock samples
from the volcano. The ROV also has a video camera so that scientists on the bridge
can see what is happening inside the crater of the volcano.
The CTD probe allows scientists to collect information on water salinity, temperature
and composition at different depths.
Seismic refraction is a geophysical technique used to determine the structure beneath
the surface of the Earth. This information will tell the extent of the debris avalanche
that was detected during the 2003 survey.
A debris avalanche is a sudden and rapid movement of rock and other debris(e.g.
vegetation) driven by gravity. It may result from the collapse of the side of an
oversteepened volcano or gravitational collapse of unconsolidated sediments. They
are one of the most hazardous but least common volcanic events. The deposits from
a debris avalanche are usually made up of a chaotic mixture of material of all sizes
resulting in a characteristic "hummocky" (lumpy) topography.
A pyroclastic flow is a hot fast-moving mixture of rock fragments, ash, and gases
which flow down the sides of a volcano.
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