What is a seismograph?
A seismograph is an instrument used for recording the intensity and duration of an earthquake.
What is the Ring of Fire?
The 'Ring of Fire' is a volcanic chain surrounding the Pacific Ocean. The 'Ring of Fire' is famous for its regular earthquake and volcanic activity. More than half of the world's active volcanoes above sea level form part of the ring.
The Pacific Plate, an oceanic plate that forms the bed of the Pacific Ocean, is surrounded by a number of continental plates including the North American plate, South American plate, Philippine plate, the Australian-Indian plate and the Eurasian plate. The movement of these plates create zones of subduction (e.g. where the Pacific and Eurasian plates meet). This leads to the formation of volcanoes and the occurrence of earthquakes.