FUTUREVOLC: From forecasts towards early warning – the importance for Europe of improved understanding of seismicity in Iceland

Christopher Bean (1) Eva Eibl (1) Kristin Vogfjord (2) Freysteinn Sigmundsson (3), and the FUTUREVOLC team (1) Seismology Lab., School of Geological Sciences, University College Dublin. (chris.bean@ucd.ie, eva.eibl@ucdconnect.ie)(2) Icelandic Meteorological Office (vogfjord@hi.is)(3) Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland (fs@hi.is)

If we could predict eruptions, we would!

Linear system Input A -> Output XInput B -> Output Y(A+B) -> (X+Y)

and

Input A -> Output XInput cA -> Output cX

<- Not satisfied on volcanoes

<- Not satisfied on volcanoes

Volcanic systems are non-linear (=> very difficult to predict)

… But the system is not random – so we can use forecasting on Volcanoes

• Phenomenological approach

• Understanding the physics & chemistry of the system (modelling)

• ‘Missed’ eruptions & false alarms are inevitable

... How about early warning (not forecasting) based on early eruption detection?

• FUTUREVOLC attempting to implement an early warning system based on eruption initiation for glacier covered volcanoes.

From Kristin Vogfjord

Question: What do we need for Early Warning?

Answer: (1) An understanding of background seismicity

(2)To understand the ‘fingerprint’ seismic signals of sub-glacial eruption initiation.

Typical pre-eruptive volcano-seismic events (1)(non glacial)

• Long Period (low frequency), long duration events

Repeating LP-events. Unfiltered waveforms (z-component) of LP-events recorded at a broad band station 1.5 km northwest of the epicentres. K. Jónsdóttir

Mýrdalsjökull glacier (Myr) in South Iceland, atop Katla volcano

Proposed alternative model for LP events at western Mýrdalsjökull

K. Jónsdóttir, PhD thesis

LP event recorded in Southern Vatnajökull

Data from Vatnsfell, 82km from source

Closest station, Kálfafell, 23kmfrom source

K. Jónsdóttir, PhD Thesis

Propagation path effects, Mt Etna

Bean et al, in review

Typical pre-eruptive volcano-seismic events (2)(non glacial)

• Tremor (sometimes harmonic)

What about fluid ‘bursts’?

S. Kedar, PhD Thesis, 1996

S. Kedar, PhD Thesis, 1996

So in this case the tremor is path related …

Tremor on Arenal, Costa Rica. Lesage et al , 2006

Current model for tremor at Arenal …

Seismic signals generated by colliding icebergs at the Antarctic Ice Sheet. MacAyeal et al, 2008

In Iceland – what about the ice?

Muller et al, 2005

Iceberg interacting with the coast, Dronning Maud Land, Antarctica

Initial Work: Tremor from a Jökulhlaup (glacial flood)

Increasing amplitude, station SKR & JOK on Sept. 2nd 2012

SKR: Guralp CMG-3 ESP = bb JOK: Guralp CMG-3 ESP = bb

Initial Work: Tremor from a Jökulhlaup

Initial Work: Tremor from a Jökulhlaup

Summary

• Long Period events might be:– Ice falls?– Magma– Steam (with strong path effects)

• Tremor might be:– Ice interactions– Water floods – Magma

=> We need better resolution tremor observation networks …

Arrays, Nunataksx2, Glacier sensorx2

Western Vat.

We plan to:

• Locate tremor events using array data

• Separate the seismic wavefield (multiple sources)

• Track speed of tremor migration

• Track glacier deformation and translation

• Compare tremor with Jökulhlaups & water chemistry

Proposed thematic integration …

Topic:

Quantitatively compare tremor at volcanoes covered with ice (FUTUREVOLC) with tremor at MED-SUV volcanoes