[lemma=feature] □
[lemma=feature] [□]
[lemma=feature] (□ | □)
Volcanic vents within the caldera are visible in the image and include Vulcan , on a peninsula on the west side of the bay , and Rabalanakaia and Tavurvur ( the circular purple feature near the mouth of the bay ) on the east side . Thre grabenlike feature near V501 probably is associated with a swarm of shallow earthquakes that occurred just north of Tennant during 1981 . Furthermore , the fact that bell-shaped objects are excavated in settlements and from features near water is a pattern shared with small dotaku . A widely accepted theory that relates most of the geologic features near the Earth 's surface to the movement and interaction of relatively thin rock plates . Crowley Lake is the dark feature near the south edge of the map .