Surge

Surge denotes a sudden, brief increase in a quantity or intensity within a system. It can describe a sharp rise in power, price, demand, water levels, or population movement, as well as a rapid onset of a phenomenon before returning to baseline.

In electrical engineering, a surge refers to a transient spike in voltage or current that lasts a short time and can damage equipment. Protective devices such as surge protectors or arresters are used to limit or redirect these transients.

Hydrology and meteorology use the term to describe elevated water levels, most often due to storms. A storm surge is an abnormal rise in sea level caused by winds and atmospheric pressure during tropical cyclones, which can exacerbate coastal flooding, especially with high tides.

In medicine and public health, a surge describes a rapid influx of patients, cases, or demand for services. Health systems plan for surge capacity to scale resources such as beds, staff, and equipment during emergencies or outbreaks.

In glaciology and geology, a glacier surge is a short-lived acceleration of glacier flow that advances the ice front. Glacial surges are characterized by rapid speed changes and often occur irregularly over months to years.

In economics and consumer services, surge pricing refers to dynamic price increases during periods of high demand, used by ride-hailing, hospitality, and e-commerce platforms to balance supply and demand.