A jet of material from active regions that reaches coronal heights and then either fades or returns into the chromosphere along the trajectory of ascent. Surges typically last 10 to 20 minutes and ten
d to recur at a rate of approximately 1 per hour. Surges are linear and collimated in form, as if highly directed by magnetic fields.
A ring-shaped cloud of gas and suspended solid debris that moves radially outward at high velocity as a density flow from the base of a vertical eruption column accompanying a volcanic eruption or cra
ter formation.
(1) Rapid increase or decrease in flow or water level. (2) Abrupt acceleration of glacier flow accompanied by a dramatic forward movement of the glacier terminus.
A short-lived, frequently large-scale, increase in the rate of movement of the ice within a glacier. Ice velocities may increase 10 to 100 times above normal flow rates. In some surges, the terminus o
f a glacier rapidly advances. Although not all glaciers surge, those that do often surge with some sort of a periodicity.