Surging

Surging is the rapid and transient increase in the forward movement, flow, or pressure of a system. In common usage it can describe abrupt increases in water, air, electric power, or other quantities, often followed by a return to normal levels.

In glaciology, a surge refers to episodic accelerations of glacier flow, sometimes moving much faster than usual over months. Triggered by internal dynamics and basal conditions, surges can transport large amounts of ice and reshape landscapes when they end.

In hydrology and civil engineering, surge describes transient pressure or flow increases in pipes and channels. Water hammer is a related phenomenon caused by sudden valve closure or pump start/stop, generating pressure waves that can damage infrastructure. Surge management uses devices like surge tanks, repressurization, controlled valve actuation, and surge protection equipment.

In fluid machinery, surge also describes unstable operating regions in compressors and turbines (for example, compressor surge) arising from pressure-volume flow interactions.

In electrical systems, a power surge is a brief spike in voltage or current, often from switching events, lightning, or faults. Protective devices such as surge protectors and properly rated equipment mitigate damage.

See also: surge (disambiguation), water hammer, surge tank, electrical surge protector.