explosion-dominated eruptions can produce dramatic (but often short-lived) surface changes around the eruption site, such as large pyroclastic and plume deposits produced as gas exsolves from lava fountains. the 1997 pillan eruption produced a wide deposit of dark, silicate material and bright sulfur dioxide. the tvashtar eruptions of 2000 and 2007 generated a tall plume that deposited a ring of red sulfur and sulfur dioxide wide. despite the dramatic appearance of these features, without continuous resupply of material, the vent surroundings often revert to their pre-eruption appearance over a period of months (in the case of grian patera) or years (as at pillan patera).