What is a helicorder?

Answer 1

A helicorder is a type of seismograph that records seismic activity, particularly used to monitor earthquakes and other ground movements. It creates a continuous graphical representation of ground motion over time, displaying the amplitude and frequency of seismic waves. The device typically consists of a pendulum or mass suspended on a spring, which moves in response to ground vibrations, and a recording pen that marks the movement on a rotating drum or digital medium. Helicoidal recordings are crucial for understanding seismic events and their impacts.