Daily Update: The
volcanic world of the "galloping lobster"
24 deg 28S
Longitude: 69 deg 54E
Wind Direction: SE
Wind Speed: 15 Knots
Sea State 3
Swell(s) Height: 6 Foot
Sea Temperature: 78°F (25.9°C)
Barometric Pressure: 1019.0 MB
Visibility: 16+ Nautical Miles
Shrimp galloping over
curtain-folded lava flow
By Amy Nevala
Today we stood on top of a volcano - or rather, ROV Jason did.
Through the vehicles remote cameras we explored the
rocky summit of Knorr Seamount, a submarine volcano we mapped
several days ago. This large seamount lies nearly mid-way
between the Edmond and Kairei hydrothermal vent fields in
the rift valley of the Central Indian Ridge.
a short CTD Tow-yo last night, the Plume Team identified a sizeable
particle plume near one of several summit craters. Intrigued
by the plume, this afternoon we lowered Jason and began searching
the volcanic terrain for the vent source.
Imagine draining the Indian Ocean and hiking on this
volcano. You would wander in a giant, jumbled rock garden that
stretches for miles. We saw three types of lava rock formations
here, with names that describe their shapes: pillow-shaped lava;
smooth sheet flows, and ropy lavas that twist like pulled taffy.
Volcanologists -- scientists who study volcanoes -- generally agree that the shape of lava flows is determined by
several factors: the speed of the flowing lava, its chemical composition,
the slope that it flows over, and the temperature of the molten
Some of the lava glistened as Jasons lights hit its glassy surfaces. This
glass suggests that it is young lava, by geologic standards. Id guess
the youngest lava here is probably at least 50 years old, said Geologist
Dan Fornari. But its hard to tell just by looking at seafloor lava
whether it is 100 years old or 1000 years old.
The rocky summit is largely a biological desert.
An occasional fish zigzagging by the camera or a fat anemone provided
a visual feast and elicited shouts from scientists like hey, a fish! One of the more comical and fascinating
creatures we saw was the cherry-red shrimp that one biologist dubbed the galloping
lobster. In reality this six-inch shrimp swims, although it resembles a
horse galloping across a field as it moves its legs through the water.
We will spend the next few hours tonight searching
for a hydrothermal vent on Knorr Seamount. If we find one, we may
stay for more sampling. Otherwise, we will return to the Edmond
Vent Field for one last dive for sampling with ROV Jason.
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