Wie bereits erw\u00e4hnt, stellen die immensen Tiefen der Subduktionszonen eine H\u00fcrde f\u00fcr Forscher:Innen dar. In diesen Tiefen ist es unm\u00f6glich, die f\u00fcr Erdbebenforschung relevanten Parameter, wie Porosit\u00e4t, Fluidansammlungen, Bewegungen von Fluiden oder Temperatur direkt zu messen. Mithilfe magnetotellurischer Daten, lassen sich diese Parameter allerdings indirekt auch bis in gro\u00dfe Tiefen erfassen.<\/p>\n\n\n\n
Das Ger\u00e4t dazu hier an Bord von SO294 hei\u00dft OBMT. Was auf den ersten Blick aussieht wie ein OBS (und streng genommen auch den gleichen Schwimmk\u00f6rper besitzt) dient in Wahrheit einem v\u00f6llig anderen Zweck: n\u00e4mlich der Aufzeichnung von Ozean-Boden-Magneto-Tellurik Daten, (kurz eben: OBMT). Es misst auf dem Meeresboden keine seismische Aktivit\u00e4t, sondern das sich st\u00e4ndig ver\u00e4ndernde elektromagnetische Feld der Erde. Das spinnen\u00e4hnliche Aussehen verdankt das OBMT seinen vier Armen, an denen Elektroden befestigt sind, die das Ein- und Aussetzen zu einer kleinen Herausforderung machen.<\/p>\n\n\n\n Die vom OBMT gesammelten Daten zeichnen ein Bild des elektrischen Widerstands im Boden. Dieser wird n\u00e4mlich von verschiedenen geophysikalischen Parametern bestimmt, die wiederum auf die Beschaffenheit der Sedimente und Kruste hindeuten. Somit lassen sich Fluidbewegungen bestimmen, oder erh\u00f6hte Temperaturen im Boden lokalisieren. Elektromagnetische Messungen durch unsere OBMT\u2019s liefern also eine wertvolle Erg\u00e4nzung zur Charakterisierung der Erdbeben-Bruchzone hier vor Vancouver Island.<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Zum kr\u00f6nenden Abschluss dieses Abschnitts gibt es noch die M\u00f6glichkeit an der kreativen Ader unserer Wissenschaftlerinnen teilzuhaben, die sich zuweilen w\u00e4hrend der Nachtschichten \u00e4u\u00dfert (und sich mit zunehmender Zeit auf See zu intensivieren scheint).<\/p>\n\n\n\n Elisa und Luisa genie\u00dfen das Releasen von geleasten Releasern.<\/em><\/p>\n\n\n\n (von Elisa Klein)<\/em><\/p>\n\n\n\n When we have hydroacoustic survey on the program, most of us on board have a little time to breathe. The newly created energy during such a phase went directly into a legendary ping-pong tournament in the hangar of FS SONNE (\u201cHangar-Games\u201d). The next phase of the OBS-deployment was scheduled a short time later – and was, however, hampered by stormy wind and weather conditions.<\/p>\n\n\n\n As already mentioned, the immense depths of the subduction zones are a hurdle for researchers. At these depths it is impossible to directly measure parameters relevant for earthquake research, such as porosity, fluid accumulation, movement of fluids or temperature. Therefore, we take the detour via magneto-telluric measurements.<\/p>\n\n\n\n The instrument for this here on board SO294 is called OBMT. What at first sight looks like an OBS (and strictly speaking also has the same float) actually serves a completely different purpose: the recording of ocean-bottom magneto-telluric data (OBMT for short). It does not measure seismic activity on the ocean floor, but the Earth’s constantly changing electromagnetic field. The OBMT owes its spider-like appearance to its four arms, to which electrodes are attached, making deployment and retrieval a bit of a challenge.<\/p>\n\n\n\n <\/p>\n\n\n\n The data collected by the OBMT paint a picture of the electrical resistance in the ground. This is in fact determined by various geophysical parameters, which in turn indicate the nature of the sediments and crust. Thus, fluid movements can be determined, or elevated temperatures in the ground can be localized. Electromagnetic measurements by our OBMT’s thus provide a valuable addition to the characterization of the earthquake rupture zone here off Vancouver Island.<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n To top off this section, we have the opportunity to share in the creative streak of our scientists, which sometimes manifests itself during the night shifts (and seems to intensify the more time we spend at sea):<\/p>\n\n\n\n Elisa and Luisa enjoy the releasing of leased releasers (by Elisa Klein<\/em>).<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":" —–english version below——— Wenn zwischendurch mal einige Tage hydroakustische Kartierung auf dem Programm steht, haben die meisten von uns an Bord ein bisschen Zeit zum Durchatmen. Die neu gesch\u00f6pfte Energie w\u00e4hrend einer solchen Phase floss direkt in ein legend\u00e4res Pingpong-Turnier im Hangar des FS SONNE ein (Hangar-Games). Die n\u00e4chste Phase des OBS- Aussetzens stand kurze […]<\/p>\n","protected":false},"author":239,"featured_media":152,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-136","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-naturgefahren-aus-dem-ozean"],"_links":{"self":[{"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/posts\/136","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/users\/239"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/comments?post=136"}],"version-history":[{"count":6,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/posts\/136\/revisions"}],"predecessor-version":[{"id":193,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/posts\/136\/revisions\/193"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/media\/152"}],"wp:attachment":[{"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/media?parent=136"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/categories?post=136"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-json\/wp\/v2\/tags?post=136"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.oceanblogs.org\/so294-clocks\/wp-content\/uploads\/sites\/90\/2022\/10\/20221021_194247.jpg\")
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Einen denkw\u00fcrdigen Sonnenuntergang konnten wir im Anschlussvor dicht an der K\u00fcste genie\u00dfen. (Photo credits: April Houweling).<\/figcaption><\/figure>\n\n\n\nOBS I did it again…!<\/strong><\/h2>\n\n\n\n
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<\/figure>\n\n\n\nOBMT \u2013 everything is in flow<\/strong><\/h2>\n\n\n\n
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Afterwards, we were rewarded with a sunset to remember, close to the coast of Vancouver Island (Photo credits: April Houweling). <\/figcaption><\/figure>\n\n\n\n