Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Alkor	AL565	23.09.2021 - 30.09.2021		Baltic Sea Western Baltic Sea

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Geersen Jacob	Institut fur Geophysik der Universitat Kiel	Kiel	Kiel

Ziel der Reise / Objectives of Cruise:

The cruise AL 565 was carried out as a marine geophysical field trip for students of the degree program 'Physics of the Earth System' at Kiel University. The purpose of this cruise was for the students to gain experience in collecting marine geophysical data including the handling of measurement devices, processing the data as well as interpreting and presenting the results. It took place in the western part of the Baltic Sea during 23. - 30. September 2021 (Fig. 1.2) starting and ending at the GEOMAR Pier, Kiel. One stopover was made near Eckernforde harbor to collect one senior scientists (24.09.2021). Survey areas were Bay of Strande, Bay of Eckernforde, parts near western and northern Fehmarn and the Bay of Mecklenburg. The first survey area was the Bay of Strande where multibeam data was collected to detect anchor tracks at the seafloor. The survey was interrupted due to other ships anchoring too close to the survey area but was continued two days later. In the Eckernforde Bay the echo sounder EK80 was used to investigate possible gas seepage. Two profiles were taken during different sea levels. Furthermore, bathymetric data was recorded at Mittelgrund to survey pockmarks, and east of Mittelgrund as well as at southern parts of Eckernforde Bay in order to map benthic habitat. Additionally, five seafloor samples were taken with the grab there. The next survey area was west of Fehmarn where multibeam data was used to search for seabed pockmarks. Afterwards, in the Bay of Mecklenburg, six grab samples were taken at the 'Blinkerhugel' as well as images of the seafloor using an underwater drone to find manganese crusts. Two more multibeam surveys were recorded in this region. At a neighboring mound seven additional grab samples were taken and the drone took images of the seafloor for a second time. After that a multibeam survey area was recorded to map a dune field North of Fehmarn. During the last night, the long EK80 profile from the Bay of Eckernforde was acquired for a third time. Multiple CTD measurements were taken during the entire cruise for postprocessing of the multibeam data.

Messungen / Measurements