RAINFALL TRIGGERING OF VOLCANIC ERUPTIONS. WE PROPOSE TO US THE HISTORIC ERUPTION AND PRECIPITATION RECORDS AS WELL AS MODERN OBSERVATIONS FROM THE GLOBAL PRECIPITATION MEASUREMENT MISSION (GPM) AND FROM INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR) TO INVESTIGATE THE EFFECT OF PRECIPITATION ON VOLCANIC SYSTEMS. WE WILL IDENTIFY EXTREME PRECIPITATION EVENTS IN THE PRECIPITATION RECORDS AND USE STATISTICAL METHODS TO SEARCH FOR CORRELATIONS WITH ERUPTION OCCURRENCE. WE WILL IDENTIFY ERUPTIONS THAT HAVE OCCURRED DAYS TO MONTHS AFTER PRECIPITATION EVENTS AND CAN BE ATTRIBUTED TO PRECIPITATION-INDUCED CHANGES IN THE PORE-FLUID PRESSURE IN THE ROCKS SURROUNDING THE MAGMA RESERVOIR. WE WILL USE FINITE ELEMENT MODELLING OF PORE-FLUID PRESSURE DIFFUSION TO TEST MODELS FOR ERUPTION TRIGGERING BY TENSILE FAILURE OF THE RESERVOIR WALL. FOR MODERN TRIGGERED ERUPTIONS WE WILL CONSTRAIN THE MODELS USING PRECIPITATION FORM GPM OBSERVATIONS AND SURFACE DISPLACEMENTS FROM INSAR. THIS STUDY IS MOTIVATED BY OBSERVATIONS AT CERRO AZUL VOLCANO GALAPAGOS AND MERAPI VOLCANO INDONESIA SHOWING STRONG CORRELATIONS BETWEEN PRECIPITATION AND ERUPTIONS. THE PROJECT DELIVERABLES ARE (1) A CATALOGUE OF RAINFALL-TRIGGERED ERUPTIONS SINCE 1851 AND (2) A METHODOLOGY TO INCLUDE PRECIPITATION INFORMATION INTO VOLCANIC HAZARD ASSESSMENT. INTELLECTUAL MERITS: THE PROPOSED PROJECT WILL DEMONSTRATE THAT PORE-FLUID PRESSURE CHANGES CAN TRIGGER MAGMA CHAMBER FAILURE. BROADER IMPACTS: THE PROPOSED PROJECT WILL PAVE THE WAY FOR THE INCORPORATION OF GPM-MEASURED PRECIPITATION AND SIMULATED PORE-FLUID PRESSURE VARIATIONS INTO PROBABILISTIC ERUPTION FORECASTING APPROACHES FOR THE NISAR ERA.