Daily Update: Looking for a volcano
23 deg 52.68S
Longitude: 69 deg 35.81E
Wind Direction: Variable
Wind Speed: 5-10 Knots
Sea State 2-3
Swell(s) Height: 5-7 Foot
Sea Temperature: 78°F (25.9°C)
Barometric Pressure: 1014.3 MB
Visibility: 3-5 Nautical Miles
By Amy Nevala
Geologists Dan Fornari and Susan Humphris will spend a sleepless night
collecting rocks from what appears to be a large seafloor
volcano on the axis of the Central Indian Ridge, located
about 40 nautical miles south of the Edmond field.
Pulling their dredges from the Indian Ocean, they will look for fresh
basalt, a glassy black rock that forms when hot volcanic lava
hits icy seawater. The glassy basalt is a sign that the volcano
has been recently active.
It is possible that this mountain on our maps is merely an uplifted block of
crust but the shape is a dead-ringer for an active submarine volcano, said
Our bathymetric maps show that this volcano is 20
miles long and 10 miles wide, with an elevation of 4,264 feet (1300
meters) -- about a third of the height of Mount Rainier in Washington
state. No other features of this type exist within hundreds of
miles of our location on the Central Indian Ridge.
Studying this volcano gives us more clues about how the mid-ocean ridge
works, said Dan.
Volcanoes form along Earths sixteen large and several small plates, which float on
a partially molten layer below them. The plates movement and interaction
is called plate tectonics. Periodically the plate boundaries pull apart, collide
or slide past or beneath one another, triggering dramatic forces, such as earthquakes
and volcanic eruptions.
We decided to head to the volcano tonight after ROV
Jasons depth sensor
stopped working while collecting mussels and other vent animals at the Edmond
Its impossible to know where we are in depth with respect to Medea
without it, said ROV Jasons Chief Pilot Will Sellers. It also limits
our ability to collect samples or make close seafloor observations.
Medea is Jasons teammate. It always hovers about 15 to 20 meters above
Jason, absorbing the movements from the ship. Medea and Jason are connected by
a 30-meter cable and need to maintain close contact for efficient operations
on the seafloor.
When you think about it, its amazing that this maze of wires and
sensors we call ROV Jason, connected to the ship by a 10 kilometer fiber optic
cable, works at all, said Dan. We take technology for granted these
days, and for the past month weve been used to going to work on the bottom
of the ocean nearly every day as if it was routine.
As a matter of fact, it is routine. Almost every
day of the year, ROV Jason, Alvin or
deep submergence vehicles operated by three other nations worldwide
are exploring the seafloor.
For U.S. scientists, going to the depths of the ocean
using Jason or in Alvin is
routine, thanks to the innovative engineering and operational expertise
of the National Deep Submergence Facility at Woods Hole Oceanographic
Institution. They have been providing deep submergence capabilities
for scientists and engineers for over 30 years.
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