Bathymetric map: A chart of ocean
floor depths, similar to topographic maps on land.
Caldera: A depression formed at the summit
of a volcano caused by collapse when magma is removed from the reservoir
Chemosynthesis: The process by which
microbes mediate chemical reactions to produce into energy. In contrast
to photosynthesis, because chemosynthesis does not require sunlight.
Contour profile: A cross-section
of topography along a given line.
Degree: A unit of angular distance. There
are 360 degrees in a circle (as on a compass).
Deposit feeder: Animals that consume
small pieces of plant and animal material that settle to the ocean floor
from the water column.
Epicenter: The point on the Earth's surface
from which earthquake waves seem to radiate, located directly above the
true center of the earthquake at depth.
Earthquake swarm: A sequence of
many small earthquakes (10's to 1000's), all of similar size (<M4)
and within a relatively short period of time (hours to weeks). Earthquake
swarms are often recorded during volcanic activity.
Hydrophone: An instrument used to record
sound under water.
Hydrothermal vent: A hot spring
on the seafloor.
Latitude: Angular distance on the Earth's
surface measured north or south of the Equator.
Lava: Molten rock after it has erupted from
a volcano onto the Earth's surface.
Longitude: Angular distance on the surface
of the Earth measured east or west from the prime meridian at Greenwich,
rock that is underground before it has erupted onto the Earth's surface.
Microbes: Single-celled living organisms,
such as bacteria and archaea.
Mid-ocean ridge: A type of tectonic
plate boundary where two tectonic plates are moving apart (also called
a "spreading center"). Volcanic activity creates a ridge at
Minute: A unit of angular distance that is
one-sixtieth of a degree.
Observatory: A site for long-term scientific
ROPOS: The name of the remotely operated vehicle
usually used at NeMO. ROPOS stands for Remotely Operated Platform for
Rumbleometer: (pronounced rum-ble-om'-i-ter)
A seafloor instrument that measures temperature and pressure (among
other things) to help monitor submarine volcanoes.
Seamount: An undersea mountain rising over
1000 meters above the surrounding seafloor.
Seismometer: An instrument that detects
ground movement from earthquakes.
Sessile: Permanently attached at the base;
fixed in one place and unable to move around.
Spreading center: See mid-ocean
Subduction zone: A type of tectonic
plate boundary where two tectonic plates are converging (moving toward
each other) and one plate is forced under the other.
Sulfide chimney: Formations made
of sulfide minerals deposited directly from hydrothermal vent fluid at
high-temperature seafloor hot springs.
Symbiotic: The relationship of different
organisms in a close association that is mutually beneficial. Many vent
animals have symbiotic relationships with chemosynthetic microbes.
Tectonic plates: Large intact pieces
of the Earth's outer rocky layer that move in relation to one another.
Most of the Earth's earthquakes and volcanoes are located near plate boundaries.
Transform fault: A type of tectonic
plate boundary where one plate slides past another.
Triangulation: Method of finding a
position with distances or angles from known points.