 During an eruption, the sea temperature around the island may increase from just above freezing to about .Historic stations and huts on the island are Hoyberg, Vera, Olsbu, Puppebu (cabin), Gamlemetten or Gamlestasjonen (the old weather station), Jan Mayen Radio, Helenehytta, Margarethhytta, and Ulla (a cabin at the foot of the Beerenberg).A regulation dating from 2010 renders the island a nature reserve under Norwegian jurisdiction.