people. Both the Japanese Meteorological Agency (JMA) and Kyoto University's Sakurajima Volcanological Observatory (SVO) monitors the volcano's activity. Since 1995, Sakurajima has only erupted from its summit with no release of lava. Monitoring techniques at Sakurajima: Likely activity is signalled by swelling of the land around the volcano as magma below begins to build up. At Sakurajima, this is marked by a rise in the seabed in Kagoshima Bay – tide levels rise as a result. As magma begins to flow, melting and splitting base rock can be detected as volcanic earthquakes. At Sakurajima, they occur two to five kilometres beneath the surface. An underground observation tunnel is used to detect volcanic earthquakes more reliably. Groundwater levels begin to change, the temperature of hot springs may rise and the chemical composition and amount of gases released may alter. Temperature sensors are placed in bore holes which are used to detect ground water temp. Remote sensing is used on Sakurajima since the gases are highly toxic – the ratio of HCl gas to SO2 gas increases significantly shortly before an eruption. As an eruption approaches, tiltmeter systems measure minute movements of the mountain. Data is relayed in real-time to monitoring systems at SVO. Seismometers detect earthquakes which occur immediately beneath the crater, signaling the onset of the eruption. They occur 1 to 1.5 seconds before the explosion. With the passing of an explosion, the tiltmeter system records the settling of the volcano. Ecuador The Geophysics Institute at the National Polytechnic School in Quito houses an international team of seismologists and volcanologists whose responsibility is to monitor Ecuadors numerous active volcanoes in the Andes Mountains of Ecuador and in the Galápagos Islands. Ecuador is located in the Ring of Fire where about 90% of the world's earthquakes and 81% of the world's largest earthquakes occur. The geologists study the eruptive activity for the volcanoes in the country, especially Tungurahua whose volcanic activity restarted on 19 August 1999, and several major eruptions since that period, the last starting on 1 February 2014. Mitigations Going beyond predicting volcanic activity, there are highly speculative proposals to prevent explosive volcanic activity by cooling the magma chambers using geothermal power generation techniques. See also Decade Volcanoes Deep Earth Carbon Degassing Project Earthquake prediction Istituto Nazionale di Geofisica e Vulcanologia United States Geological Survey Jökulhlaup Ice cauldrons Notes External links WOVO (World Organisation of Volcano Observatories) IAVCEI (International