Project GAKKELDEEP: DEPAS ocean-bottom seismometer operations at the Gakkel Ridge in 2018-2019

• Main Authors: Schlindwein, Vera, Kirk, Henning, Hiller, Marc, Scholz, John-Robert, Schmidt-Aursch, Mechita
• Format: Dataset
• Language: English
• Published: PANGAEA 2022
• Subjects: 8F_GKD01; 8F_GKD02; 8F_GKD03; 8F_GKD04; Binary Object; Clock skew; Code; Comment; Cruise/expedition; Date/time end; Date/time start; DEPAS; ELEVATION; Event label; gakkel ridge; Arctic Ocean; Hydrophone; serial number; Hydrophone gain; Hydrophone polarity; Hydrophone type; LATITUDE; LONGITUDE; OBS; Ocean bottom seismometer; ocean-bottom seismometer; Optional event label; Passive seismology; Principal investigator; Project; PS115/2_4-1; PS122/1_2-30; PS115/2_5-1; PS122/1_2-22; PS115/2_6-1; PS122/1_2-23; PS115/2_7-1; PS122/1_2-24; Recorder; Recorder type; Sampling rate; Seismometer; Seismometer gain; Seismometer type; Station label; Arctic; Berichte zur Polar- und Meeresforschung; Reports on Polar and Marine Research; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.947045; https://doi.org/10.1594/PANGAEA.947045

Gakkel Deep is a pilot project that installed a network of four broadband ocean bottom seismometers (OBS) near Gakkel Deep, the deepest depression in the Arctic Ocean, at the eastern end of the ultraslow spreading Gakkel Ridge. The area is covered year-round by sea ice. In order to enable a safe recovery of the OBS in a sea ice covered ocean, the OBS were modified to include a positioning system that allows to track the instruments at meter accuracy during descent and ascent and when stuck beneath ice floes. This pilot studied aimed at testing the recovery procedure of the OBS, checking the performance of the modified instrument design, getting an overview of ambient seismic noise at the bottom of the Arctic Ocean and at contributing to a better understanding of the origin of the Gakkel Deep depression with more than 3000 m of topography. The network is shaped as a rectangle with 8 km and 10 km side length and is centered at about 82°N 119.5°E at water depths between 3600 m and 4100 m. It is positioned slightly to the east of the present plate boundary in an area with volcanic structures. Instruments from the German Instrument Pool of Amphibian Seismology (DEPAS) were deployed during RV Polarstern cruise PS115/2 on September 15, 2018. Instrument recovery was completed during RV Polarstern cruise PS122/1 on September 27, 2019. The data set contains about 377 days of continuous records at 250 Hz sample rate. The station locations were determined with Ultra Short Baseline (USBL) ranging, the accuracy is approx. 10 m.