MOLE: A Multidisciplinary Observatory and Laboratory of Experiments in Central Italy

Abstract

The structure and mechanics of active Low Angle Normal Faults (LANFs) have for decades b s) been posing questions—in particular, if low angle normal faults accommodate crustal extension, and if they generate large magnitude earthquakes, or if they move aseismically. To shed new light on these challenging questions, MOLE intends to drill (down to 4–5 km) an active LANF in the Umbria-Marche sector of the northern Apennines (Fig. 1) and to establish a deep borehole observatory. The target site offers a unique opportunity to reach a LANF at drillable seismogenic depth to unravel the “low angle normal fault mechanical paradox” (Wernicke, 1995; Axen, 2007). In order to discuss the scientific background and plan the MOLE project, ixty-two scientists from various research fields attended an international workshop in Spoleto, Italy, on 5–8 May 2008. The workshop focused on the following goals that need to be achieved: (I) to collect new observational data at depth for constraining the fault zone structure; (II) to perform laboratory experiments with gouge and fault zone materials to understand frictional properties and weakeningmechanisms; (III) to record microearthquakes at distance comparable to the source radius, and (IV) to obtain stress and strain measurements and geochemical data in and near the fault zone at depth to understand the mechanics of earthquakes and faulting.

Keywords

• MOLE