Dark spot on Saunders Island in February

In a satellite image from 20th February 2016, a dark spot appears on Saunders Island which indicates that recent activity of some kind had taken place. This could be that Mount Michael had been going through an eruptive phase, or it could simply be elevated ground temperatures volcanic in origin.

Dark spot which appears on Mount Michael on 20th February. SOURCE: Aqua/MODIS/NASA.