{"id":168,"date":"2020-10-23T15:22:25","date_gmt":"2020-10-23T13:22:25","guid":{"rendered":"https:\/\/site.uit.no\/seamstress\/?p=168"},"modified":"2020-10-23T15:22:25","modified_gmt":"2020-10-23T13:22:25","slug":"heat-and-stress-both-tectonic-all-this-expedition-is-about","status":"publish","type":"post","link":"https:\/\/site.uit.no\/seamstress\/2020\/10\/23\/heat-and-stress-both-tectonic-all-this-expedition-is-about\/","title":{"rendered":"Heat and stress (both tectonic) \u2013 all this expedition is about"},"content":{"rendered":"

We had a rough transit from Troms\u00f8 to the Fram Strait. Up to 6 meters waves and strong winds slowed us down to 6 knots (normally this type of vessel navigates at 10-11 knots). So we left Ramfjord at about 15:00 on Saturday (the 17th<\/sup>) and arrived on site (The Vestnesa Ridge on the west-Svalbard continental margin) 3 days after, to start with the experiment straight ahead.<\/p>\n

For this cruise we have designed experiments to test hypothesis. The first idea we want to test, the core of the SEAMSTRESS project, is that the opening of the mid-ocean ridges compresses the sediment against Svalbard and this leads to high fluid pressures that eventually result is gas expulsions. Just like in a closed casserole with boiling water in the kitchen. On the Vestnesa Ridge the gas expulsions has occurred everywhere for the last 20.000 years (since the last big ice age). But the release of gas remains abundant only towards the east of the margin. So what happened towards the west of the margin? This is what we are experimenting about…<\/p>\n

We have selected 4 stations along the margin to measure the pressure of the water and the gas in the sediment. For this we will use the Ifremer piezometer I mentioned in the previous post. We need to carefully select the locations to put the instrument because we do not want to reach a fault (we want the background pressure of the fluids). The ship Kronprins Haakon and those steering it are amazingly good at keeping position within 2 m. We are having fun! We also survey the ground with the sub-bottom profiler (acoustic waves) to be sure we are not aiming for any dangerous structure. In one of the stations we also placed 5 ocean bottom seismometers carefully around the piezometer. We want to search for a relationship between micro seismicity, pressure pulses in the sediment and pressure changes due to tides.\"\"<\/p>\n

Photo: The crew and the French colleagues prepare the piezometer to go in the water for the first time.\u00a0<\/em><\/strong><\/p>\n

So far, we have placed 2 piezometers that have hopefully been recording data over 3 days. The plan is to recover them between today and tomorrow. If time and weather allows we would like to put them back for the remaining 2 stations.<\/p>\n

In-between, we have been measuring the temperature of the Earth. Temperatures are key for modeling the zone where gas hydrates form. From these temperatures we can calculate how fast the heat is transfer through the sediment and then we can predict movement of warmer overpressured fluids from deep sediment toward the seafloor.<\/p>\n

 <\/p>\n

\"\"<\/p>\n

Photo: Sunil preparing the big thermometer<\/strong><\/em><\/p>\n

Since we arrived the sea has been calm and generous. We hope the Viking gods continue to be on our side.<\/p>\n

 <\/p>\n

Text and photos Andreia Plaza-Fa<\/em>verola<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

We had a rough transit from Troms\u00f8 to the Fram Strait. Up to 6 meters waves and strong winds slowed us down to 6 knots (normally this type of vessel navigates at 10-11 knots). So we left Ramfjord at about 15:00 on Saturday (the 17th) and arrived on site (The Vestnesa Ridge on the west-Svalbard … Continue reading Heat and stress (both tectonic) \u2013 all this expedition is about<\/span><\/a><\/p>\n","protected":false},"author":997,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-168","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/posts\/168","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/users\/997"}],"replies":[{"embeddable":true,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/comments?post=168"}],"version-history":[{"count":2,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/posts\/168\/revisions"}],"predecessor-version":[{"id":172,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/posts\/168\/revisions\/172"}],"wp:attachment":[{"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/media?parent=168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/categories?post=168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.uit.no\/seamstress\/wp-json\/wp\/v2\/tags?post=168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}