Predictability of volcano eruption: Lessons from a basaltic effusive volcano

Abstract

[1] Volcano eruption forecast remains a challenging and controversial problem despite the fact that data from volcano monitoring significantly increased in quantity and quality during the last decades. This study uses pattern recognition techniques to quantify the predictability of the 15 Piton de la Fournaise (PdlF) eruptions in the 1988 -2001 period using increase of the daily seismicity rate as a precursor. Lead time of this prediction is a few days to weeks. We formulate a simple prediction rule, use it for retrospective prediction of the 15 eruptions, and test the prediction quality with error diagrams. The best prediction performance corresponds to averaging the daily seismicity rate over 5 days and issuing a prediction alarm for 5 days. 65% of the eruptions are predicted for an alarm duration less than 20% of the time considered. Even though this result is concomitant of a large number of false alarms, it is obtained with a crude counting of daily events that are available from most volcano observatories.

The interplay between collapse structures, hydrothermal systems, and magma intrusions: the case of the central area of Piton de la Fournaise volcano

“…Collombet et al (2003) first called attention to the stable location of the seismogenic volume beneath the summit since the beginning of monitoring, but they only noted that it was regarded as "the main path for the magma flow toward the surface" and did not discuss further its structural significance. On the other hand, Grasso and Zaliapin (2004) and Traversa and Grasso (2009) suggest that the location of the volcanic seismicity does not reflect directly that of the magma intrusion tip or path, but rather a diffuse release of the background stresses in the edifice under the effect of the perturbation caused by the injection of magma. Similar observations have been reported by Rubin et al (1998) at Kilauea, Pedersen et al (2007) in Iceland and by Toda et al (2002) in the Izu islands.…”

First Results from the UnderVolc High Resolution Seismic and GPS Network Deployed on Piton de la Fournaise Volcano

“…The research topics covered by the project are: highprecision seismic velocity monitoring from seismic noise (Brenguier et al 2008), processes of dike injection (Taisne et al 2011), dike-induced deformation (Peltier et al 2011), microseismicity relocation (Got et al 2008, shear-wave splitting monitoring (Gerst and Savage 2004), long-period event source inversion (De Barros et al 2011), flank instability/ rock fall processes (Hibert et al forthcoming), and predictability of volcanic eruptions (Grasso and Zaliapin 2004). Since the beginning of the UnderVolc project station deployment (September 2009), five eruptions occurred at Piton de la Fournaise volcano (5 November 2009, 14 December 2009, 2 January 2010, 14 October 2010, and 9 December 2010).…”

Seismic signature of a phreatic explosion: hydrofracturing damage at Karthala volcano, Grande Comore Island, Indian Ocean

“…Duration and seismicity rate of the early May swarm are both similar to those associated with the magma intrusion or the eruption at Piton de la Fournaise (Lénat 1989;Sapin et al 1996;Aki and Ferrazzini 2000;Collombet et al 2003;Grasso and Zaliapin 2004). The PF seismicity swarms, that immediately precede eruptions, lasted for from 0.5 to 36 h, with a 4 h mean duration, with a 130 events/h mean rate for VT events (Grasso and Zaliapin 2004). As the Karthala swarm in May 1991 lasted about this, with about 160-200 events/hr which are within the characteristic of intrusion patterns on PF volcano, an intrusion might have occurred in May 1991.…”