Future eruptive crisis scenarios a Volcán de Fuego: what can we infer from the historic record? Rüdiger Escobar Wolf PIRE meeting Nov. 13, 2009
My goal Discuss scenarios with people Investigate when they would choose to leave Different perspectives?
But what scenarios? What could the volcano do? What do we know? What can we infer? How can we put this into scenarios?
Eruptions VEI since 1500 AD According to the GVP 4 3 VE EI 2 1 1500 1600 1700 1800 1800 2000 Year
Review of the catalogue of events Reviewed > 70 references (30 were considered at the end). Try to infer size and details of the crisis development
Very rich and informative The year of [fifteen hundred] eighty one, on December twenty six, the volcano started to throw fire more than usual, and it was so much what it threw, and with such a fury, the next day of December twenty seven, through a mouth that it has in the highest part, that from the abundant ash that came out, the air became black and thick, such that people couldn t see each other [in Antigua Guatemala] ash reached many leagues from Guatemala, in the province of Xoconusco, where the trees were found to be covered by it That fire caused much damage it ruined a pueblo de indios named San Pedro, two leagues from [Antigua] Guatemala, although there were no deaths, because it happened during the day, and prevented by fear, all the indios escaped with time, abandoning their homes Antonio De Ciudad Real (ca. 1585) writing about the 1581 1582 eruptions.
Details relevant to estimate the size or the eruption the ash that the Fuego volcano threw darkened the sun and it was necessary to light the candles at eleven in the morning and the ash was so much that on roofs and on the ground it accumulated to more than eight fingers [~ 7 8 cm in Antigua Guatemala] Santos (ca. 1720) writing about the 1705 eruption. The year of 1706 it threw so much ash, without throwing out fire, that it [the ash] reached more than thirty leagues [120 210 km]; as I saw it in the village of Rabinal [~ 80 km from the volcano] Ximenez (ca. 1717) writing about the 1706 eruption.
Details relevant to estimate the size or the eruption having the growth of the fire started around eleven at night it started to cause a slow tremor on the ground and a special noise or murmur, which came from doors, windows, doorknockers, frames, and everything that was hanging from the walls Arana (ca. 1718) writing about the 1717 eruption. and this with an earth trembling, that was felt more than four leagues [16 28 km] from the volcano, which started many days before [the volcano] started to throw the fire, and lasted for many days afterwards, such that all the doors and windows were shaking, and the doorknockers made noise Ximenez (ca. 1717) writing about the 1717 eruption.
Details relevant to estimate the size or the eruption the murmurs, loud sounds and retumbosof that night of August 28 could be heard throughout neighboring provinces around Guatemala to distances of 80 to 90 leagues, and even it was written from the Petenjail, which is more than 160 leagues, that the same night loud noises like shots could be heard towards Cancu [Cancun] which is in the province of the Zendales[Chiapas], as if a great battle was taking place. In the village of Sonsonate, which is more than 40 leagues away from this city [Antigua Guatemala], not only were the noises heard, but also the flames were seen The ashes from the volcano flew to distances of 50 to 60 leagues, but the majority of it fell on the province of San Antonio Suchitepequez, where on August 29th at nine in the morning no light beam had been seen because the horizon was covered with very dense smoke and ash, which fell in such a quantity that it rose above the ground more than one cuarta[ca. 15 20 cm], and the trees with the weight [of the ash] were breaking and falling Anonimous(ca. 1717) writing about the 1717 eruption.
But there is also interesting information about eruptions that may not have been as large as we thought On August 27, 1737 the volcano of Guatemala [Fuego volcano] started to throw fire, it continued for a few days, with many mouths opening on its flanks, from which smoke and fire came out Juarros (1752 1820) writing about the 1717 eruption. This is the only piece of evidence about the eruption. According to Feldman (1993), it is not mentioned in any contemporary document. Is it really one of Fuego s large events?
Ash dispersal modeling and MLE? Probability of exceeding 1 cm of ash accumulation for a VEI 4 eruption between the months of June and October.
Revisiting the catalogue VEI Year
The evolution of crises in the past
The evolution of crises in the past
Potential precursor and warning / evacuation Evacuation? (first chance) Size? Hazard Reaching the town Vandalism? Evacuation? (second chance) Next activity state? Hazard second phase. End of all scenarios / branches yes Large Small PF Ash > 10 cm yes Large PF Ash > 10 cm Backgr. Nothing no Small Nothing yes Backgr. Large PF yes Large no Small Backgr. Ash > 10 cm Nothing no Small Backgr. Large no Small Backgr. Days Several (4-8) hours Several (24-48) hours
In short Review the catalogue (important for modeling risk). Characterize the past crises at Fuego. Use historical accounts to communicate crisis scenarios. Work in progress