The mainstay of volcanic monitoring in the Eastern Caribbean is the seismograph network, which is used to detect earthquakes. As magma makes it way to the surface of the Earth, this movement tends to crack the surrounding rock causing small earthquakes known as volcanic earthquakes. A volcanic earthquake swarm is a series of small earthquakes, which occurs close to a volcano. Although these earthquakes are usually very small they happen within a few kilometres of the Earth’s surface and may be strongly felt. Some volcanic earthquakes may also be caused as water flashes into steam (i.e. it boils instantaneously, turns into steam and expands rapidly), cracking the rocks around it. An increase in volcanic earthquakes is usually a clear signal that the volcano is restless.
The Eastern Caribbean Seismograph Network (ECSN) operated by the SRC consists of over 60 instruments that comprise a mixture of three-component broadband stations, three-component strong motion stations, three-component and single-component short-period stations. Data are transmitted in real or near real-time to our headquarters in Trinidad. When earthquake activity increases, anywhere in the region, data can be processed locally in real time.