© ICDP, the International Continental Scientific Drilling Program, 1996-2021

www.icdp-online.org

Krafla Magma Drilling Project

Europe, Atlantic Ocean, Iceland, Krafla

new full-proposal: ICDP-2015/08
for the funding-period starting 2015-01-15
by John C. Eichelberger, Freysteinn Sigmundsson, Paolo Papale, Susan C. Loughlin
Abstract
What if we knew where magma is located under a volcano and its current state? Such information would transform volcanology. For extreme events, we typically know where the vulnerabilities are: people, lifelines, and critical infrastructure, but seldom do we know the “source term” beforehand. For restless calderas such as Campi Flegrei, Italy and Yellowstone, USA, the threat is silicic magma within the caldera itself. Great effort has gone into finding such bodies through surface measurements. “Discovery” is declared when consensus is achieved. But there is a difference between consensus and knowledge. By following certain conventions in finding magma bodies (aseismic volume, seismic attenuation, Mogi source location, water and CO2 content of melt inclusions) and depicting them in accepted ways (oblate spheroids or lenses with an impossible solid/liquid boundary discontinuity), we perpetuate myths that mislead even ourselves. The consensus view of the Long Valley Caldera, USA, magma reservoir has evolved over 40 years from a 104 km3 balloon to two tiny pockets of magma, in part because drilling revealed a temperature of 100oC at 3 km depth over the “balloon”. Oil and gas exploration is free of fanciful reservoirs because there is ground truth. Geophysics and geology define a possible reservoir and a well is drilled. If oil is not there, the model needs revision. The situation is worse for conditions of magma storage. The heretofore-unknowable roof zone of magma chambers has been invoked for separating melt from crystals and/or for accumulating vapor and evolved magma leading to eruption. Anything is possible when there are no data. The accidental (but technically remarkable) drilling discovery of rhyolite magma at 2,100 m depth under Krafla Caldera, Iceland by Landsvirkjun Co. and the Iceland Deep Drilling Project opens the door to properly detect magma and to understand how magma evolves, energizes hydrothermal systems, and erupts. We propose to continuously core through the margin of the magma body, accompanied by state-of-the-art geophysics, geochemical analyses and 3-D mass/heat transport modeling. Gradients in phase assemblage and composition will provide definitive tests of models of mass/heat transfer and magma evolution. By knowing “the answer”, techniques for finding magma will likewise be tested, making Krafla an international magma laboratory. Additionally, the observed high permeability and sustained power output from the magma body’s margin implies self-sustained thermal fracturing, i.e., an “Enhanced Geothermal System” an order of magnitude more powerful than conventional geothermal.
Scientific Objectives
  • The objectives are to learn the physical/chemical/mechanical conditions of magma under Krafla caldera and to understand how it is forming, how it is coupled to the overlying hydrothermal system, and under what conditions it could erupt. We will also use this exceptional opportunity to explore how best to detect active magma bodies within calderas and whether such bodies will support sustained high-power output through self induced thermal fracturing.
Keywords
Europe, ICDP-2015/08, Iceland, KRAFLA, Magma
Location
Europe, Atlantic Ocean, Iceland, Krafla: 65.71587, -16.76452

© ICDP, the International Continental Scientific Drilling Program, 1996-2021

www.icdp-online.org