IMAGES: Multi Ray Imaging, Gravity and Boxcoring
Multibeam imaging is a type of echo location using multiple sensors to create a 3D image of the sea floor under a ship as it passes, with the sensors mounted on its hull. The resulting image is about 1 km wide depending on the depth and may reveal traces of glacial activity, trawl marks or indicators of petroleum, such as pockmarks from methane bursts.
A Gravity corer is a long cylinder that is lowered from a ship down into the sediments on the ocean floor. It is able to collect a core that preserves layers of sedimentation up to 5-6 meeters deep. A gravity core may contain silt and clay from as long back as 8-10 thousand years ago. The stratas within the core can be read as an vertical cronological archive of the condition and history of the site it was sampled from.
A box corer is a box that is lowered into the shallower sediments providing a larger but shallower area of study. Both of the core sampling techniques can provide geological and biological information for the trained observer.
Images from TUNU VII expedition to NE Greenland Aug/Sept 2022