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Uncovering the Secrets of an Earthquake:
Multidisciplinary Study of Physico-Chemical
Processes During the Seismic Cycle
(acronym: USEMS)
Principal Investigator:
Giulio Di Toro
Hosting Institution:
ERC Starting Grant – Stage 2 – Interview - Bruxelles, 10 October 2007
Outline of the USEMS project
1. Motivation
2. Methodology
3. Main results and applications
Outline of the USEMS project
1. Motivation
2. Methodology
3. Main results and applications
1.Motivation
Earthquakes
(EQs, red)
and
landslides
(blue)
threaten our
continent.
http://www.seismo.
ethz.ch/hazard/risk
/flyers/Mediterrane
an.html
Fault surface
Hypocenter
• EQs and landslides are due to slip on surfaces.
• Friction is the key to understand the physics of EQs
and landslides.
• Destructive EQs nucleate at 10-15 km depth so are
investigated remotely via seismology.
• Indirect approach allows only limited understanding
of EQ physics.
Deformation conditions during EQs are extreme:
1. High slip rates (1 - 10 m/s)
2. Large displacements (up to 20 m)
3. High stresses (> 20 MPa)
These conditions are so extreme that they belong to
a new frontier in material science.
NO apparatus in the world can simultaneously
reproduce ALL these deformations conditions.
The USEMS will bridge this technological and
scientific gap by:
1) Installing a world class versatile rock friction
apparatus to reproduce the seismic cycle in the lab.
2) Looking inside the EQ engine (exhumed faults).
With this new and direct multidisciplinary approach,
we aim to understand EQ physics but also other
friction-related processes of geological and
industrial interest.
Physico-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
methane:
CO2 + 2H2  CH4 + O2
(method patented by the Italian National Research Council, ref. P. Plescia,
Team Member of the USEMS).
This process of industrial interest requires systematic
investigation that will become possible using the rock
friction apparatus we propose in USEMS.
Outline of the USEMS project
1. Motivation
2. Methodology
a) Field studies
b) Experimental studies and
installation of the HVRFA
c) Microstructural studies
d) Numerical models
3. Main results and applications
2. Methodology
a) Field studies of exhumed seismic faults will be
performed using state of the art techniques (e.g., LIDAR,
goCad) to quantify the structure of seismic faults.
LIDAR
goCad
200 m
Seismic
Fault
b) Experimental studies and the High Velocity
Rock Friction Apparatus (HVRFA)
We will investigate the mechanical properties of faults
during the EQ cycle by performing experiments on
natural rocks.
5 cm
2 cm
Seismic fault
Specimens
The world class, new-conception HVR-Friction App.
Lateral
view
Axial
load
actuator
Axial
load
cell
Axial
column
Upper
specimen
Lower
specimen
Secondary
motor
Torque
cell
Rotary
column
Main motor
1m
HVRFA
Frame
HVRFA will simulate the EQ cycle
(and landslides) in the lab,
including:
1. EQ cycle accelerations and slip
rates (1 mm/s - 9 m/s).
2. Infinite displacements.
3. High Stresses (up to 50 MPa).
The HVRFA has an
unprecedented range of loading
conditions allowing us to study
processes never investigated
before.
Exper. will produce mechanical data, test theoretical
friction laws and explore new frictional mechanisms.
Theoretical
friction law
3
Shear
stress
(MPa)
2
1
Experimental data
0
0
5
10
15
20
Normal stress (MPa)
Nielsen, Di Toro, Hirose, Shimamoto, JGR, in press
c) Microstructural Studies will determine the deform.
mechanisms operating in nature and experiments.
50 mm
50 mm
SEM
Nature
Seismic melts
Experiment
50 mm
Di Toro et al., Science, 2006
SEM
50 mm
d) Numerical models (calibrated by field, experimental,
theoretical and microstructural data) will produce
synthetic seismograms to compare to real seismograms
and use in EQ hazard studies.
Di Toro et al., Nature 2005
MICROSTRUCTURAL STUDIES
FIELD STUDIES
FIELD SURVEY
& LIDAR
500 m
goCad
FE-SEM
FAULT
ROCKS
50 mm
EXPERIMENTS & THEORY
SAMPLE PREP.
MODELING
SYNTHETIC
SEISMOGRAMS
EXP. DATA
RUPTURE DYNAMICS
MODELS
THEORETICAL AND
CONSTITUTIVE EQ.
HVRFA
Outline of the USEMS project
1. Motivation
2. Methodology
3. Main results and applications
3. Anticipated results of USEMS
• Scientific: understanding of the physics of
earthquakes and landslides, and application to EQ
and landslide hazard.
• Technological: 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.
• Industrial: the apparatus allows the investigation of
friction-related processes of economic interest such
as production of hydrocarbons from rocks.
Team Members of the USEMS project
(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).
Budget of the USEMS project