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Marine geophysical instrumentation: Videos from the deployment cruise 2012

Written by Karin Sigloch on . Posted in Technology

Deployments of geophysical instruments during the first RHUM-RUM Cruise Sep.-Oct 2012, aboard Marion Dufresne (cruise MD192, Leg2)

Films produced by Emmanuel Pons of the University of La Réunion.

Our main type of instrumentation: Ocean-bottom seismometers record the subtle motions of the ocean floor until we return in 2013. We are particularly interested in recording waves from earthquakes that occurred thousands of kilometers away, which illuminate the mantle deep beneath La Réunion. We are also interested in smaller regional earthquakes and the daily noise on the ocean floor.

Cruise RHUM-RUM 2012, Marion Dufresne MD192, Leg2

Voir la vidéo: Préparation d'un OBS DEPAS - 5'05"

Voir la vidéo: Tests acoustiques de largueurs DEPAS - 2'31"

Voir la vidéo: tests acoustiques de largueurs INSU - 2'42"

Voir la vidéo: Déploiement de l'OBS DEPAS RR22  - 1'26" 

Voir la vidéo: Déploiement de l'OBS RR28 INSU  - 3'00" 

Voir la vidéo: Déploiement l'OBS RR29 INSU  - 1'56"

 Voir la vidéo: Dernier déploiement (OBS DEPAS RR24) - 2'02"

 Voir la vidéo: Cérémonie du dernier déploiement (OBS DEPAS RR24) - 4'05" 

Films made by Guilhem BARRUOL  Université de La Réunion / IPGP

Cruise RHUM-RUM 2013, campagne Meteor M101

 Voir la vidéo: OBS RR50 INSU recovery, 23/11/2013 - 4'15"

 Voir la vidéo: OBS RR38 INSU recovery, 19/11/2013 - 1'40"

 Voir la vidéo: OBS RR40 INSU recovery, 20/11/2013 - 5'37"

 

Bathymetry: the ship constantly surveyed the depth and shape of the ocean floor by sending and recording acoustic pings. Only a small fraction of the world's ocean floor has been mapped with a state-of-the-art multi-beam bathymeter such as the one on the Marion Dufresne, and new discoveries are common. Our colleague Dass Bissessur from the Mauritius Oceanography Institute explains the discovery of a picture-perfect seamount (in French).

Video: Dass Bissessur explains a new undersea volcano discovered at Waypoint 38 by bathymetric mapping

The magnetometer measures the magnetization of the seafloor, which gives information about how and when the ocean basins formed. It gets towed behind the ship and recorded constantly, except when the ship stopped. Here the sailors are redeploying the magnetometer after the end of a seismometer deployment.

Video: Deployment of the magnetometer - 1'16"

The only instrument recovery during the cruise: an absolute pressure sensor was tested on the seafloor for several hours by our colleague Wayne Crawford from IPG Paris. Next year, we will return to recover our 57 ocean-bottom seismometers in a similar way.

Video: Test deployment and recovery of an absolute pressure sensor - 4'26"

Video: Wayne Crawford explains the signal recorded by his absolute pressor sensor on the seafloor (in French) - 5'37"