The Hawaiian Volcano Observatory celebrated the 30th anniversary of Mauna Loa's last eruption (in 1984) on March 25, 2014, underscoring that it has been a realtively quite 3 decades at the world's largest active volcano.
A tiltmeter, is a type of instrument used to detect any kind of tilt in the structure to which it is attached. Most tiltmeters use an air bubble in a liquid-filled tube, much like a typical carpenter's level, but are equipped with sensitive electronics that can detect even the tiniest change in tilt. They either sound an alarm or transmit the data to a remote monitor or other device.
The science of monitoring volcanoes is still growing. Some volcanologists are using satellites to monitor active volcanoes. For example, the path of the volcanic plume erupted at Pinatubo was tracked using AVHRR weather satellites.ome rock movements may be associated with the rise of magma beneath an awakening volcano. Volcanologists that monitor gases often use a correlation spectrometer (COSPEC) that measures sulfur dioxide (SO 2) in plumes rising out of volcanic craters.