A massive 100 million-year-old ancient extinct volcano was discovered beneath the Pacific Ocean.
Scientists discovered a new seamount near the Johnson Atoll in the Pacific Ocean during a seafloor mapping mission.
The mapping mission aimed at helping delineate the outer limits of the US continental shelf.
About the seamount
The yet-unnamed sea-mount, located about 300 kilometres southeast of the uninhabited Jarvis Island, lies in one of the least explored areas of the central Pacific Ocean.
The summit of the seamount rises 1100 meters from the 5100 metre-deep ocean floor.
Mr. Gardner and his team used multi-beam echo-sounder technology to create detailed images of the seafloor. The team was able to map the conical seamount in its entirety.
A seamount is typically formed from extinct volcanoes that rise abruptly and are usually found rising from the seafloor.
About multi-beam echo-sounder technology
Multibeam sonar sounding systems is also known as swathe. It was originated for military applications.
A multi-beam echo-sounder is a device typically used by hydrographic surveyors to determine the depth of water and the nature of the seabed.
The Sonar Array Sounding System (SASS) was developed in the early 1960s by the US Navy, in conjunction with General Instrument to map large swaths of the ocean floor to assist the underwater navigation of its submarine force.
In order to determine the transmit and receive angle of each beam, a multi-beam echo-sounder requires accurate measurement of the motion of the sonar relative to a cartesian coordinate system. The measured values are typically heave, pitch, roll, yaw, and heading.
To compensate for signal loss due to spreading and absorption a time-varied gain circuit is designed into the receiver.
For deep water systems a steerable transmit beam is required to compensate for pitch, this can also be accomplished with beam forming.
Where: beneath the Pacific Ocean
What: was discovered
When: 8 September 2014