18
Jun

A global bathymetry map derived from satellite altimetry and shipboard sounding data

  • 18 June 2021

Webinar, 18 June 2021, 10.00-11.00am

The seafloor is a fundamental feature of our planet, with the oceans accounting for ∼71% of Earth’s surface area. Only ∼20%, however has been (publicly) mapped at fine spatial resolution (≤800 m) using shipboard sounding methods. As such, its surface remains more poorly understood than that of many other planet’s moons, and asteroids.

This lack of knowledge is unfortunate given that seafloor bathymetry is of fundamental importance in many aspects of earth and biological sciences. In lieu of this lack of shipboard data, we use sea surface slope measurements from satellite altimetry to derive a global marine gravity map, which is then used to “predict” bathymetric depths everywhere. These predicted depths are combined with freely available shipboard sounding compilations to produce a global bathymetry model ­­­– SRTM15+. The spatial resolution of predicted depths in our latest version (2.1) is ~ 6-8 km in the deep ocean with root-mean-square depth errors of ~ 150 m in the deep ocean and ~ 180 m landwards of the continental rise.

This model and the related gravity maps have been used to better map the global mid-ocean ridge system, chart thousands of previously uncharted seamounts and study the tectonic fabric of the seafloor. Moving forward, the resolution and accuracy of predicted bathymetry will continue to improve as data continues to be collected by the currently active altimeters SARAL/AltiKa and CyroSat-2. While NASA’s swath altimeter SWOT mission, due to launch later this year, with its smaller footprint and additional cross‐track slope measurement, could improve the gravity accuracy by perhaps a factor of 5 further improving the accuracy and spatial resolution of predicted bathymetry.


Event Type - Webinar

Date and Time: 18 June 2021, 10.00am - 11.00am
Fees:
Members - $50+gst
Non-Members: $120 +gst (join us now and save)

CPD Allocation: 1 Point