HMRG Deep
Encyclopedia
The HMRG Deep was discovered in 1997 by a team of scientists from Hawaii. Its depth (10,732 meters) is thought to be second or third only to the Challenger Deep
and possibly Horizon Deep
, currently the deepest known places in the ocean. It lies along the Mariana Trench
, 200 kilometers to the east of the Challenger Deep and 145 km south of Guam
.
survey of the seafloor around Guam, discovering what is believed to be the second or third deepest location in the world's oceans; its existence was confirmed in 2001 and it was temporarily named HMRG Deep. In the same research mission, scientists found previously undiscovered faults, landslide
s, and mud volcano
es.
The data that confirmed the discovery were collected using the HAWAII MR1
mapping system. This mapping system has the ability to record both bathymetry and sidescan data at the same time. The two vessels that this system was used on were RIV Moana Wave in 1997 and RIV Melville in 2001.
motion as previously thought, but through a north-south convergence
of the Caroline plate
and the Pacific plate
, in which the Caroline plate is subducting
. A group of scientists have hypothesized that the great depth of the Mariana Trench, the Challenger Deep, and the HMRG Deep is due to a tear in the subducting Caroline plate, causing deformation of the Pacific plate above. This tear would be located to the south of Guam, the same location of the deepest portion of the Mariana Trench. The tear would lead to unusual regional tectonics, another possible reason for the extreme depth. Scientists were alerted to the presence of the tear by the depth of strike-slip earthquakes, which were occurring too deep for them to be in the overriding plate.
The HMRG Deep lies at the intersection of the East Santa Rosa Bank Fault and a trench axis south of Guam.
ages 18 and younger could compete. The new deep area name had to have a reference to either Guam or Mariana Islands history, culture, or language; additionally, the students had to submit a paragraph that explained how their chosen name was important. The selected name would appear on geologic
and bathymetric
maps. The contest ended on July 14, 2009. As of August 2009, the new name has not been announced yet.
Challenger Deep
The Challenger Deep is the deepest known point in the oceans, with a depth of to by direct measurement from submersibles, and slightly more by sonar bathymetry . It is located at the southern end of the Mariana Trench near the Mariana Islands group...
and possibly Horizon Deep
Tonga Trench
The Tonga Trench is located in the South Pacific Ocean and is deep at its deepest point, known as the Horizon Deep.The Tonga Trench is a convergent plate boundary. The trench lies at the northern end of the Kermadec-Tonga Subduction Zone, an active subduction zone where the Pacific Plate is being...
, currently the deepest known places in the ocean. It lies along the Mariana Trench
Mariana Trench
The Mariana Trench or Marianas Trench is the deepest part of the world's oceans. It is located in the western Pacific Ocean, to the east of the Mariana Islands. The trench is about long but has a mean width of only...
, 200 kilometers to the east of the Challenger Deep and 145 km south of Guam
Guam
Guam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...
.
Discovery
In 1997, the Hawaii Mapping Research Group conducted a detailed sonarSonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
survey of the seafloor around Guam, discovering what is believed to be the second or third deepest location in the world's oceans; its existence was confirmed in 2001 and it was temporarily named HMRG Deep. In the same research mission, scientists found previously undiscovered faults, landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
s, and mud volcano
Mud volcano
The term mud volcano or mud dome are used to refer to formations created by geo-excreted liquids and gases, although there are several different processes which may cause such activity. Hot water mixes with mud and surface deposits. Mud volcanoes are associated with subduction zones and about 700...
es.
The data that confirmed the discovery were collected using the HAWAII MR1
HAWAII MR1
The HAWAII MR1 is a seafloor imaging system developed by the Hawaii Mapping Research Group in 1991. HAWAII MR1 is short for HIGP Acoustic Wide Angle Imaging Instrument, Mapping Researcher 1. This system is the first to use all-digital signal processing...
mapping system. This mapping system has the ability to record both bathymetry and sidescan data at the same time. The two vessels that this system was used on were RIV Moana Wave in 1997 and RIV Melville in 2001.
Formation
The HMRG Deep was most probably formed, not through transform faultTransform fault
A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere, is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction. Furthermore, transform faults end abruptly...
motion as previously thought, but through a north-south convergence
Convergent boundary
In plate tectonics, a convergent boundary, also known as a destructive plate boundary , is an actively deforming region where two tectonic plates or fragments of lithosphere move toward one another and collide...
of the Caroline plate
Caroline Plate
The Caroline Plate is a small tectonic plate located north of New Guinea. It forms a subduction zone along the border with the Bird's Head Plate and the Woodlark Plate to the south. A transform boundary forms the northern border with the Pacific Plate. Along the border with the Philippine Sea Plate...
and the Pacific plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
, in which the Caroline plate is subducting
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
. A group of scientists have hypothesized that the great depth of the Mariana Trench, the Challenger Deep, and the HMRG Deep is due to a tear in the subducting Caroline plate, causing deformation of the Pacific plate above. This tear would be located to the south of Guam, the same location of the deepest portion of the Mariana Trench. The tear would lead to unusual regional tectonics, another possible reason for the extreme depth. Scientists were alerted to the presence of the tear by the depth of strike-slip earthquakes, which were occurring too deep for them to be in the overriding plate.
The HMRG Deep lies at the intersection of the East Santa Rosa Bank Fault and a trench axis south of Guam.
Renaming
A competition was held by Dr. Patricia Fryer, her doctoral student Sam Hulme, and Linda Tatreau to rename the HMRG Deep; Dr. Fryer was involved in the discovery of the spot. Students from Guam and the Northern Mariana IslandsNorthern Mariana Islands
The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands , is a commonwealth in political union with the United States, occupying a strategic region of the western Pacific Ocean. It consists of 15 islands about three-quarters of the way from Hawaii to the Philippines...
ages 18 and younger could compete. The new deep area name had to have a reference to either Guam or Mariana Islands history, culture, or language; additionally, the students had to submit a paragraph that explained how their chosen name was important. The selected name would appear on geologic
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and bathymetric
Bathymetry
Bathymetry is the study of underwater depth of lake or ocean floors. In other words, bathymetry is the underwater equivalent to hypsometry. The name comes from Greek βαθύς , "deep", and μέτρον , "measure"...
maps. The contest ended on July 14, 2009. As of August 2009, the new name has not been announced yet.
External links
- HMRG homepage, under the University of HawaiiUniversity of HawaiiThe University of Hawaii System, formally the University of Hawaii and popularly known as UH, is a public, co-educational college and university system that confers associate, bachelor, master, and doctoral degrees through three university campuses, seven community college campuses, an employment...
- HIGP homepage (Hawaii Institute of GeophysicsGeophysicsGeophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
and Planetology), also under the University of Hawaii