13 March 2015 - Svein Østerhus, Pictorial report from Antarctic expedition

Post date: 9 févr. 2015 12:52:48

Friday 13 March 2015, we are very happy to have Svein Østerhus from Uni Research Climate as a guest speaker.

Svein will show photos and share with us his experience from field work on the Antarctic ice shelves, drilling through 800 m thick ice to obtain unique oceanographic measurements.

After the talk, dinner and drinks will be served in the canteen.

We hope that many of you will join us this evening.

Both members and non-members are very welcome!

Program

  • 18:00-18:30 BGF Annual meeting with election and information about upcoming events
  • 18:30-19:15 Svein Østerhus:
    • On expedition to the world's largest floating body -
    • the Filchner-Ronne Ice Shelf in Antarctica
      • See abstract below.
  • 19:30-24:00 Dinner and drinks in canteen

Location: Geophysical Institute

The annual meeting and talk are free and open for everyone.

The dinner (buffet from Prestige Catering) in the canteen is also open for everyone, but costs 150,- for students, 200,- for members and 250,- for others. Drinks will be for sale at happy prices.

Please register for the dinner by email to knutfd@met.no by tuesday 10 March, and mention any dietary needs (vegetarian etc).

At the annual meeting there will be an election of the BGF board for the next 2 years. Please send an email to knutfd@met.no if you would like to be listed as a candidate.

Svein Østerhus has attended 11 expeditions to Antarctica and many expeditions in the Arctic. The overall goal has been to build a long-term observatory of the ocean currents transferring mass and heat to and from the polar regions. This lecture will deal with the scientific issues, but most of all about life and fieldwork in the cold and white wilderness.

The small Antarctic ice shelves have been dramatically thinned because of increased supply of heat from the ocean. These ice shelves play an important role in stabilization of ice sheets in Antarctica and in the production of the coldest and heaviest deepwater in the worlds oceans. The big question is what happens with the largest of them; the Ross- and Filchner-Ronne ice shelves.

In this talk I will present results from the work we are carrying out in the Filchner-Ronne area. There we have established two long-term observatories; one below 800 m thick ice on the Ronne Ice (Site 5) and one under the sea ice in the southern Weddell Sea (S2). The observatory under the Ronne ice observes variations of the ocean currents under the ice and formation of super cold Ice Shelf Water (ISW). The observatory at southern Weddell Sea is located where the super cold ISW flows into the deep ocean, forming the Antarctic Bottom Water.

These two observatories are included in a large network of ocean- and ice observatories around the Filchner-Ronne Ice Shelf. This work is carried out in cooperation with AWI and BAS. Our overarching goal is to build an observation system for early notification of ocean-induces outflow of ice sheets in Antarctica, which in turn will lead to increased sea level. Such a system must be able to be operational for many decades, and can therefore only be implemented through joint international efforts.

På tokt på verdas største flytande lekam – Filchner-Ronne isbremmen i Antarktis

Østerhus har deltatt på 11 ekspedisjonar til Antarktis og mange tokt i Arktis. Det overordna mål har heile tida vore å bygge langtids observatorium i havstraumane som fører masse og varme til og frå polarområda. Dette foredraget vil handle om dei vitskaplege problemstillingane, men mest om feltarbeidet i Antarktis med fortellingar om livet ute i isøydet.

Dei små isshelfane i Antarktis blir dramatisk tynnare på grunn av auka tilførsel av varme frå havet. Isbremmane spelar ei viktig rolle i stablisering av isdekket i Antarktis og i produksjonen av det kaldaste og tyngste vatnet i havet. Det store spørsmålet er kva som skjer med dei største; Ross- og Filchner-Ronne-isbremmane.

I dette foredraget skal eg presentere resultat frå det arbeidet vi fortida gjennomfører i Filchner-Ronne-området. Der har vi etablert to langtids-observatorium; eitt i havvatnet under 800 m tjukk is på Ronneisen (Site-5) og eitt under sjøisen i det sørlege Weddellhavet (S2). Observatoriet under Ronneisen observerer variasjonar i havstraumane under isen og danninga av det superkalde isbremvatnet (ISW, Ice Shelf Water). Observatoriet i det sørlege Weddellhavet er plassert der kor det superkalde ISW strøymer ned i djuphavet og dannar Antarctic Bottom Water.

Desse to observatoria inngår i eit større nett av hav- og is-observatorium i området rundt Filchner-Ronne-isbremmen. Dette er eit arbeid som vi utfører i samarbeid med AWI og BAS. Vårt overordna mål er å bygge eit observasjonssystem for tidleg varsling havindusert utgliding av isdekket i Antarktis, som igjen vil føre til auka havnivå. Eit slikt system må kunne vere i operasjon i mange tiår og kan difor berre realiserast med felles internasjonal innsats.