Scientists have finally discovered what's causing a Switzerland-size hole to repeatedly open up in Antarctica's sea ice.
Researchers first spotted the hole, called the Maud Rise polynya, in 1974 and 1976 in Antarctica's Weddell Sea, and since then it has reappeared fleetingly and sporadically — opening up in different sizes but in the same place, then sometimes not at all for years. This left scientists puzzled as to the exact conditions needed for the hole to form.
