MH370: Sea floor mapping a challenge, even with newest technologies

This is despite the latest and most advanced technologies that are available in the world today.

Geoscience Australia's Environmental Geoscience Division chief, Dr Stuart Minchin, said the search for MH370 is currently using the most technologically-advanced multibeam sonar system for the depths in the search area.

"Multibeam sonar systems use different frequencies for different water depths. For example, higher frequencies (>100 kilohertz/kHz) are used for shallow water and low frequencies (<30 kHz) are used for deep water.

"Water depths of up to 6km in the MH370 search area makes detailed mapping of the sea floor a challenge, even with the newest technologies.

"The sea floor in the search area has been found to be highly complex with massive undersea remnant volcanoes, canyons and seamounts," Minchin told Astro AWANI recently.

He said some finer-scale seabed features that were previously unknown and unmapped have been discovered in the process.

"For example, ridges that are 6km-wide and 15km-long which stand 1.5km above the previously known seabed, and remnant volcanoes that are 14km in diameter and 2.2km-tall.

"Volcanic mounds of 1.5km in diameter and 400m-tall as well as large depressions or pockmarks (were also) found in the sea floor (up to 800m deeper than the surrounding sea floor)," he said.

He said water depths in the search area vary from 630m in the shallowest parts and plunge to more than 6,000m in the deepest areas.

"The bathymetry data collected in the search area has shown a difference in some locations of 1,400m in depth, compared to how deep it was previously understood to be," Minchin added.

Geoscience Australia, which is providing ongoing expert advice to the search team, led by the Joint Agency Coordination Centre (JACC) and the Australian Transport Safety Bureau (ATSB), released a video titled Mapping the deep ocean: Geoscience Australia and the search for MH370, recently.

The 5:45-minute video describes in detail the processes of bathymetric mapping and side scan sonar used to gather data.