1 PITON DE LA FOURNAISE Country: France Subregion Name: Western Indian Ocean Volcano Type: Shield volcano Volcano Status: Historical Last Known Eruption: 2010 Summit Elevation: 2632 m8,635 feet Latitude: °S 21°13'51"S Longitude: °E55°42'45"E 9/13/2010 Manzoni Patrick

2 Eruptive characteristic: Central vent eruption Radial fissure eruption Explosive eruption Lava flows Debris Avalanche Lava lake eruption Flank (excentric) vent Phreatic explosion

3 WE CAN SAY, HOWEVER THAT FOR THIS PERIOD, THE DURATION OF ERUPTIONS IS GENERALLY SHORT 92 ERUPTIONS TAKE PLACE WITH DURATION LESS OF 1 YEAR. DURATI ON OF ERUPTI ONS FREQUE NCY SINCE DURATI ON OF ERUPTI ON FREQUEN CY DURATIONS OF HISTORICAL ERUPTIONS

4 POSSIBLE CYCLE OF ERUPTION DURATION, WITH 3 PEAKS: TIME INTERVAL OF 150 YEARS

5 ERUPTIVE CYCLES AND VOLUMES OF MAGMA EMITTED WE CAN DISTINGUISH 3 MAJOR CYCLES FOR THE LAST 70 YEARS: WITH 0,05 m3/s OF MEAN OUTPUT WITH 0,1 m3/s OF MEAN OUTPUT WITH 1,3 m3/S OF MEAN OUTPUT VOLUME(M3 /s)CYCLES ° CYCLE °CYCLE °CYCLE

6 RELATION BETWEEN DURATIONS OF ERUPTIONS AND PERIODS OF INACTIVITY THE DURATION OF AN ERUPTIONS HAS A DIRECT INFLUENCE ON THE DURATION OF THE FOLLOWING PERIODS OF INACTIVITY 1.<6 MONTHS < 1 YEARS 2.>6 MONTHS > 1 YEARS THE PERIOD OF INACTIVITY DECREASE TOWARDS THE PRESENT EPOCH MORE FREQUENT ERUPTION

7 INACTIVITY PERIODS THERE’S A DOWNWARD TREND OF THE REPOSE TIME AGREE WITH THE INCREASED FREQUENCY OF ERUPTION AGREE WITH THE AVERAGE VALUES OF PREVIOUS SLIDE

8 VEI (MEAN) YEAR S VOLCANIC EXPLOSIVITY INDEX WE CAN NOTE, OVER THE YEARS, THE PREDOMINANT VALUE OF “VEI” IS 2 PROBABLE ERUPTION CYCLE..? DOWNWARD TREND OF VOLCANIC EXPLOSIVITY INDEX

9 CONCLUSION: FORECASTING VOLCANIC ERUPTIONS WE CAN DISTINGUISH THREE MAJOR VOLCANIC CYCLES DURING LAST 70 YEARS. THE THIRD IS STILL IN PROGRESS. EACH CYCLE BEGAN WITH A HUGE OUTPOURING OF OCEANITE MAGMA. THE DURATION OF AN INACTIVE PERIOD IS LINKED WITH THE DURATION OF PREVIOUS ERUPTION (AND MAYBE WITH THE VOLUME OF MAGMA EMITTED DURING PREVIOUS ERUPTION). WE CAN DISTINGUISH ONE MAJOR VOLCANIC CYCLE OF DURATION IN THE LAST 370 YEARS. A FUTURE FORECAST NEED ADDITIONAL DATA, SEISMIC DATA, INSTRUMENTS FOR MONITORING OF GAS EMISSION, ECC.