ERC Starting Grant – Stage 2 – Interview - Bruxelles, 10 October 2007

Uncovering the Secrets of an Earthquake: Multidisciplinary Study of Physico-Chemical

Processes During the Seismic Cycle(acronym: USEMS)(acronym: USEMS)

Giulio Di ToroPrincipal Investigator:

Hosting Institution:

Outline of the USEMS project

1. Motivation

2. Methodology

3. Main results and applications

Outline of the USEMS project

1. Motivation1. Motivation

2. Methodology

3. Main results and applications

EarthquakesEarthquakes (EQs, red) and landslideslandslides (blue) threaten our continent.

http://www.seismo.ethz.ch/hazard/risk/flyers/Mediterranean.html

1.Motivation1.Motivation

• EQsEQs and landslideslandslides are due to slipslip on surfaces. • FrictionFriction is the key to understand the physicsphysics of EQs

and landslides. • Destructive EQs nucleate at 10-15 km depth10-15 km depth so are

investigated remotelyremotely via seismology. • IndirectIndirect approach allows only limited understandinglimited understanding

of EQ physics.

Hypocenter

Fault surface

10 km

Deformation conditions during EQs are extreme:

1. High slip rates (1 - 10 m/s1 - 10 m/s)2. Large displacements (up to 20 mup to 20 m)3. High stresses (> 20 MPa> 20 MPa)

These conditions are so extreme that they belong to a new frontier in material sciencenew frontier in material science.

NONO apparatus in the world can simultaneously reproduce ALLALL these deformations conditions.

The USEMSUSEMS will bridge this technologicaltechnological and scientific gapscientific gap by:

1) Installing a world class versatile rock friction versatile rock friction apparatusapparatus to reproduce the seismic cycle in the lab.

2) Looking inside the EQ engine (exhumed faultsexhumed faults).

With this newnew and directdirect multidisciplinary approach, we aim to understand EQ physicsEQ physics but also other friction-related processes of geological and friction-related processes of geological and industrial interestindustrial interest.

Physico-chemical processes similarPhysico-chemical processes similar to those occurring during EQs produce hydrocarbons from rocks.

During comminution of marly rocks, CO2 and H2 due to

decomposition of calcite and clays react to yield methanemethane:

CO2 + 2H2 CHCH44 + O2

(method patented by the Italian National Research Council, ref. P. Plescia, Team Member of the USEMS).

This process of industrial interestindustrial interest requires systematic investigation that will become possible using the rock friction apparatus we propose in USEMSUSEMS.

Outline of the USEMS project

1. Motivation

2. Methodology2. Methodologya) Field studiesa) Field studiesb) Experimental studies and b) Experimental studies and

installation of the HVRFAinstallation of the HVRFAc) Microstructural studiesc) Microstructural studiesd) Numerical modelsd) Numerical models

3. Main results and applications

Seismic Fault

a) a) Field studiesField studies of exhumed seismic faults will be performed using state of the art techniques (e.g., LIDAR, goCad) to quantifyquantify the structure of seismic faults.

LIDAR goCad

200 m

2. Methodology2. Methodology

b) b) Experimental studies and the High Velocity Experimental studies and the High Velocity Rock Friction Apparatus (HVRFA)Rock Friction Apparatus (HVRFA)

We will investigate the mechanical properties of faults during the EQ cycle by performing experiments on natural rocks.

2 cm5 cm

Seismic fault

Specimens

Axial load actuator

Axial column

Axial load cell

Torquecell

1 m

Upper specimen

Lower specimen

Rotary columnSecondary

motor

Main motor

HVRFAFrame

Lateral view

The world class, new-conception HVR-Friction App.The world class, new-conception HVR-Friction App.

HVRFA will simulate the EQ cycle (and landslides) in the lab, including:

1. EQ cycle accelerations and slip rates (1 1 m/s - 9 m/sm/s - 9 m/s).

2. Infinite displacementsInfinite displacements.3. High Stresses (up to 50 MPa)50 MPa).

The HVRFA has an unprecedented rangeunprecedented range of loading conditions allowing us to study processes never investigated never investigated beforebefore.

Exper. will produce mechanical datamechanical data, test theoretical theoretical friction lawsfriction laws and explore new frictional mechanismsnew frictional mechanisms.

Nielsen, Di Toro, Hirose, Shimamoto, JGR, in press

Theoretical friction law

Experimental data

Shear stress (MPa)

Normal stress (MPa)

3

2

1

00 2015105

ExperimentNatureSeismic melts

50 mm50 mm

50 50 mm 50 50 mm

50 mm50 mm

c) c) Microstructural StudiesMicrostructural Studies will determine the deform. mechanisms operating in nature and experiments.

Di Toro et al., Science, 2006

SEMSEM SEMSEM

Di Toro et al., Nature 2005

d) d) Numerical modelsNumerical models (calibrated by field, experimental, theoretical and microstructural data) will produce synthetic seismograms to compare to real seismograms and use in EQ hazard studies.

FIELD SURVEY

& LIDAR

goCadFAULT ROCKS

SAMPLE PREP.

HVRFATHEORETICAL AND CONSTITUTIVE EQ.

RUPTURE DYNAMICS MODELS

SYNTHETIC SEISMOGRAMS

EXP. DATA

MODELING

FIELD STUDIES MICROSTRUCTURAL STUDIES

EXPERIMENTS & THEORY

FE-SEMFE-SEM

50 50 mm

500 m

Outline of the USEMS project

1. Motivation

2. Methodology

3. Main results and applications3. Main results and applications

3. Anticipated results 3. Anticipated results of USEMS

• ScientificScientific: understanding of the physics of earthquakes and landslides, and application to EQ and landslide hazard.

• TechnologicalTechnological: the versatile friction apparatus is a technical challenge. Italy and the EU will become key world players in the study of EQs, landslides and high-velocity friction.

• IndustrialIndustrial: the apparatus allows the investigation of friction-related processes of economic interest such as production of hydrocarbons from rocks.

(18 researchers coordinated by the PI)

A) Field work and microstructural analyses. Giorgio Pennacchioni (Padova Univ., I), Andrea Bistacchi (Milano Bicocca Univ., I), Stefan Nielsen (INGV, I), Richard Jones (Durham Univ., UK), Karen Mair (Oslo Univ., N) and Post-Doc 1.

B) Development of the HVRFA and rock friction experiments. Terry Tullis (Brown Univ., USA), Toshiko Shimamoto (Hiroshima Univ., J), Takehiro Hirose (Jamstec, J), Antonino Tripoli, Piergiorgio Scarlato, Stefan Nielsen and Gianni Romeo (INGV, I), Post-Doc 2.

C) Modeling and theoretical analyses of field and experimental data.Stefan Nielsen (INGV, I) and Karen Mair (PGP, Univ. of Oslo, Norway).

D) Other Applications.Industrial: Paolo Plescia (CNR, I), PhD 1.Landslides: Ioannis Vardoulakis and Emmanuil Veveakis (NTUA,

Athens, Greece).

Team Members of the USEMS projectTeam Members of the USEMS project

Budget of the USEMS projectBudget of the USEMS project