In the early hours of November 11, 2018, an extremely unusual event left geologists baffled. A series of strange seismic waves rippled across the world. They originated 24 kilometers off the coast of an island near Madagascar called Mayotte. The waves passed over oceans, reaching as far as Canada and New Zealand. And experts can’t agree why it happened.
The term “seismic waves” refers to waves of energy that move through the earth. They occur due to the abrupt fracturing of rock within the planet. A variety of occurrences can lead to seismic waves, including man-made explosions, landslides, volcanic eruptions and earthquakes.
Seismology is the examination and analysis of earth’s seismic waves. Experts in the field use a variety of specialist equipment to note and measure the effects of waves and earthquakes. Seismologists record these using a variety of instruments, including accelerometers, seismometers and hydrophones.