Grand Challenges for Seismology: Relevance to Mineral Physics

1
Grand Challenges for Seismology Relevance to
Mineral Physics
Michael Wysession Department of Earth and
Planetary Sciences Washington University, St.
Louis, MO
2
Earth Science Literacy Initiative Having the
Earth Science research community endorse a single
document of what all citizens should know about
Earth Science
3
Earth Science Literacy Initiative Having the
Earth Science research community endorse a single
document of what all citizens should know about
Earth Science
Sort of like herding cats.
4
Seismological Grand Challenges Writing
Group Thorne Lay, Editor Richard C. Aster,
workshop tri-chair Donald W. Forsyth, workshop
tri-chair Barbara Romanowicz, workshop
tri-chair Richard M. Allen Vernon F. Cormier Joan
Gomberg John A. Hole Guy Masters Derek
Schutt Anne Sheehan Jeroen Tromp Michael E.
Wysession
5

• Why might this Seismology report be important for
  Mineral Physics?
• By Implication
• By Association
• By Example

6
If Mineral Physics provides the eyes for seeing
into the earth
7
Seismology provides the ears
Courtesy of J. Tromp
8
and we have lots of ears
9
and lots of sounds
KEY SEISMOLOGICAL PRACTICES 1 MONITORING DYNAMIC
PROCESSES IN EARTHS ENVIRONMENT (Courtesy of
Walter and Harris)
10
and lots of recordings!
The cumulative volume of seismic data archived at
the IRIS Data Management Center, 2008
11
KEY SEISMOLOGICAL PRACTICES 2 MULTISCALE 3D and
4D IMAGING AND MODELING OF COMPLEX EARTH SYSTEMS
Nankai trench off the Izu Peninsula, Japan
(Courtesy of UTexas, Jackson School of
Geosciences)
12
KEY SEISMOLOGICAL PRACTICES 2 MULTISCALE 3D and
4D IMAGING AND MODELING OF COMPLEX EARTH SYSTEMS
Slices from a 3D image of Okmok Volcano, Alaska
13
KEY SEISMOLOGICAL PRACTICES 2 MULTISCALE 3D and
4D IMAGING AND MODELING OF COMPLEX EARTH SYSTEMS
Velocities at depth of a recent 3D S-wave
velocity model (Courtesy of Kustowski et al.)
14
KEY SEISMOLOGICAL PRACTICES 2 MULTISCALE 3D and
4D IMAGING AND MODELING OF COMPLEX EARTH
SYSTEMS EarthScope Has provided a lot more ears
over North America
Rayleigh wave group velocities for 60,000 8-sec
waves from 3 years of continuous data (Courtesy
of Moschetti et al.)
15
Societal challenges for seismology are
concentrated in the near-surface environment
Tomographic threshold
Scattered-wave threshold
(Courtesy of Tom Jordan)
16
GRAND CHALLENGE 1. HOW DO FAULTS SLIP?
Topography of an exposed fault surface measured
in Klamath Falls, Oregon (Courtesy of E. Brodsky)
17
GRAND CHALLENGE 1. HOW DO FAULTS SLIP?
Rupture process for the 2001 Kokoxili, Tibet, (Mw
7.8) earthquake (Courtesy of Walker and Shearer)
18
GRAND CHALLENGE 1. HOW DO FAULTS SLIP?
Rupture zones of the 26 December 2004 and 28
March 2005 great Sumatra earthquakes (Courtesy of
C.J. Ammon)
19
Sidebar 1 Seismicity
Identifying repeat patterns of seismicity
(Courtesy of Waldhauser and Schaff)
20
Sidebar 2 Earthquake Rapid Warning Systems
AlertMap test showing predicted distribution of
ground shaking for the October 20, 2007, Mw 5.4
earthquake near San Jose (Courtesy of R. Allen)
21
Sidebar 3 Ambient Noise and Fault Zone Healing
Change of ground structure between seismic
stations over time, measured from
cross-correlation of microseismic noise (Courtesy
of Brenguier et al.)
22
Sidebar 4 Episodic Tremor and Slip (ETS)
Tremor event in January, 2007, corresponding
with slow slip of a few cm. Events repeat every
14 months (Courtesy of K. Creager)
23
Sidebar 5 Earthquake Prediction and
Predictability
Building devastation from the 2008 Wenchuan
earthquake in China
24
GRAND CHALLENGE 1. HOW DO FAULTS SLIP?
25
GRAND CHALLENGE 1. HOW DO FAULTS SLIP?
26
GRAND CHALLENGE 2. HOW DOES THE NEAR-SURFACE
ENVIRONMENT AFFECT NATURAL HAZARDS AND RESOURCES?
San Gabriel and Los Angeles Basins showing soil
structures as indicators of future shaking during
an earthquake (Courtesy of Thelen et al.)
27
GRAND CHALLENGE 2. HOW DOES THE NEAR-SURFACE
ENVIRONMENT AFFECT NATURAL HAZARDS AND RESOURCES?
Seismic cross section of a subsurface
clay-bounded channel (center) containing a dense
liquid contaminant (Courtesy of Gao et al.)
Meters
28
Sidebar 6 Physics-based Prediction of Ground
Motions Using Realistic Fault Rupture Models and
3D Geological Structures
Kinematic Rupture Model Dynamic Rupture Model
Ground motion intensities for a simulated M 7.7
earthquake with SE to NW rupture on a 200-km
section of the San Andreas Fault (Courtesy of
Olsen et al.)
29
Sidebar 7 Underground Nuclear Explosion
Monitoring and Discrimination
Seismic waves can distinguish explosions and
implosions from earthquakes (double couples)
(Courtesy of Dreger et al.)
30
Sidebar 8 Gas Hydrates as an Energy Source,
Environmental Hazard, and a Factor in Global
Climate Change
(Courtesy of Trehu et al.)
31
GRAND CHALLENGE 2. HOW DOES THE NEAR-SURFACE
ENVIRONMENT AFFECT NATURAL HAZARDS AND RESOURCES?
32
GRAND CHALLENGE 3. WHAT IS THE RELATIONSHIP
BETWEEN STRESS AND STRAIN IN THE LITHOSPHERE?
Plate boundary deformations, involving surface
velocities, shear strains, and mean strains for
the San Andreas System from geodetic measurements
(Courtesy of Platt et al.)
33
Sidebar 9 Remote Triggering of Earthquakes
Tiny Montana earthquakes triggered by waves from
the 2002 Mw 7.9 Denali Earthquake (Courtesy of
Manga and Brodsky)
34
Sidebar 10 Seismology and Probabilistic Hazard
for Waste Repository Siting
Kashiwazaki-Kariwa Nuclear Plant, damaged during
2007 Mw 6.6 Chuetsu earthquake
Probabilistic seismic hazard curve for Yucca
Mountain, Nevada (Courtesy of Stepp and Wong)
35
GRAND CHALLENGE 3. WHAT IS THE RELATIONSHIP
BETWEEN STRESS AND STRAIN IN THE LITHOSPHERE?
36
GRAND CHALLENGE 3. WHAT IS THE RELATIONSHIP
BETWEEN STRESS AND STRAIN IN THE LITHOSPHERE?
37
GRAND CHALLENGE 4. HOW DO PROCESSES IN THE OCEAN
AND ATMOSPHERE INTERACT WITH THE SOLID EARTH?
Average sources of long period hum
(Winter/Summer), compared to averaged wave
heights from Topex/Poseidon (Courtesy of Rhie and
Romanowicz)
38
GRAND CHALLENGE 4. HOW DO PROCESSES IN THE OCEAN
AND ATMOSPHERE INTERACT WITH THE SOLID EARTH?
Infrasonic sources monitored across Europe using
regional infrasound records for 2000-2007
(Courtesy of Le Pichon et al.)
39
Sidebar 11 Cryoseismology
Greenland events associated with outflow of major
continental glaciers (Courtesy of Ekström et al.)
40
Sidebar 12 Seismic Imaging of Ocean Structure
Imaging fine-scale (5m resolution) features of
ocean layers, revealing thermohaline circulation
eddies (Courtesy, S. Holbrook)
41
GRAND CHALLENGE 4. HOW DO PROCESSES IN THE OCEAN
AND ATMOSPHERE INTERACT WITH THE SOLID EARTH?
42
GRAND CHALLENGE 5. WHERE ARE WATER AND
HYDROCARBONS HIDDEN BENEATH THE SURFACE? Sidebar
13 Exploration Seismology and Resources Energy
and Mining
4D seismic imaging of reservoirs can show the
changing locations of hydrocarbons as they are
extracted (Courtesy of J. Louie)
43
Sidebar 14 Seismology Workforce Issues
85 of IRIS summer interns go on to geoscience
graduate school
44
Sidebar 15 Four-Dimensional Imaging of Carbon
Sequestration
Ex/ CO2 injection (8 Mton) at the Sleipner field
in the Norwegian North Sea (Courtesy of Chadwick
et al.)
45
GRAND CHALLENGE 5. WHERE ARE WATER AND
HYDROCARBONS HIDDEN BENEATH THE SURFACE?
46
KEY SEISMOLOGICAL PRACTICES 2 MULTISCALE 3D and
4D IMAGING AND MODELING OF COMPLEX EARTH SYSTEMS
Slices from a 3D image of Okmok Volcano, Alaska
47
GRAND CHALLENGE 6. HOW DO MAGMAS ASCEND AND
ERUPT?
Slices from a 3D image of Okmok Volcano, Alaska
48
GRAND CHALLENGE 6. HOW DO MAGMAS ASCEND AND
ERUPT?
Ratio of P/S velocities in the Nicaraguan
subduction zone Dark red areas show presence of
rising melts from water dehydration (Courtesy of
Syracuse et al.)
49
Sidebar 16 Four-Dimensional Monitoring of
Volcanoes Using Ambient Seismic Noise
Ex/ Changing seismic velocity just before the
1999 (left) and 2006 (right) eruptions of Piton
de la Fournaise volcano (Reunion) (Courtesy of
Brenguier et al.)
50
GRAND CHALLENGE 6. HOW DO MAGMAS ASCEND AND
ERUPT?
51
GRAND CHALLENGE 6. HOW DO MAGMAS ASCEND AND
ERUPT?
52
GRAND CHALLENGE 7. WHAT IS THE
LITHOSPHERE-ASTHENOSPHERE BOUNDARY?
Seismic velocity discontinuities beneath the
Sierra Nevada, suggesting detachment of lower
crust (continental lithosphere is more complex
than we realized) (Courtesy of Gilbert et al.)
53
GRAND CHALLENGE 7. WHAT IS THE
LITHOSPHERE-ASTHENOSPHERE BOUNDARY?
Example of seismically imaged ancient continental
lithospheric sutures, persisting to the present
(Courtesy of M. Bostock)
54
GRAND CHALLENGE 7. WHAT IS THE
LITHOSPHERE-ASTHENOSPHERE BOUNDARY?
Seismic velocity contrasts associated with the
lithosphere-asthenosphere boundary under New
England are too sharp for just temperature
(hydrated? melt?) (Courtesy of Rychert et al.)
55
Sidebar 17 Intraplate Earthquakes
Intraplate seismicity of New Madrid seismic zone
superimposed on map of topography (Courtesy of
M.B. Magnani)
56
GRAND CHALLENGE 7. WHAT IS THE
LITHOSPHERE-ASTHENOSPHERE BOUNDARY?
57
GRAND CHALLENGE 7. WHAT IS THE
LITHOSPHERE-ASTHENOSPHERE BOUNDARY?
58
GRAND CHALLENGE 8. HOW DO PLATE BOUNDARY SYSTEMS
EVOLVE?
Map of diffuse plate boundary regions (Updated
from Gordon and Stein)
59
GRAND CHALLENGE 8. HOW DO PLATE BOUNDARY SYSTEMS
EVOLVE?
Seismic tomography of upper 1000 km beneath
Western US showing disruption of subducting Juan
de Fuca plate by upwelling plume (Courtesy of R.
Allen)
60
GRAND CHALLENGE 8. HOW DO PLATE BOUNDARY SYSTEMS
EVOLVE?
Cross section from the Mantle Electromagnetic
and Tomography (MELT ) experiment showing
asymmetric crustal growth (Courtesy of MELT
Seismic Team)
61
Sidebar 18 Plate Boundary Field Laboratories
Ex/ The Nankai Trough Seismogenic Zone Experiment
(NanTroSEIZE) images the interface between the
subducting Philippine Plate and overriding
continental plate, examining conditions for
seismic/aseismic slip
62
Sidebar 19 Deep Earthquakes
Aftershocks of deep earthquakes can rupture
outside of the seismically active cores of deep
slabs, perhaps due to transient high strain rates
(Courtesy of D. Wiens)
63
GRAND CHALLENGE 8. HOW DO PLATE BOUNDARY SYSTEMS
EVOLVE?
64
GRAND CHALLENGE 9. HOW DO TEMPERATURE AND
COMPOSITION VARIATIONS CONTROL MANTLE AND CORE
CONVECTION?
Global 3D configuration of seismic velocity
heterogeneities in the mantle as imaged by
seismic tomography (Courtesy of A. Dziewonski)
65
GRAND CHALLENGE 9. HOW DO TEMPERATURE AND
COMPOSITION VARIATIONS CONTROL MANTLE AND CORE
CONVECTION?
Seismic sampling of the sub-African superplume?
Megaplume? Megapile? LLSVP! (Courtesy of Wang and
Wen)
66
Sidebar 20 The Mysterious Inner Core
3D distribution of anisotropic fabric within the
outer part of inner core there is unusual
east-west variation in velocity, attenuation, and
anisotropy (Courtesy of X. Song)
67
Sidebar 21 Planetary Seismology
Buzz Aldrin deploying a seismometer on the Moon
during the Apollo 11 mission seismometers are
planned for future missions to both Mars and the
Moon (Courtesy of NASA)
68
GRAND CHALLENGE 9. HOW DO TEMPERATURE AND
COMPOSITION VARIATIONS CONTROL MANTLE AND CORE
CONVECTION?
69
GRAND CHALLENGE 9. HOW DO TEMPERATURE AND
COMPOSITION VARIATIONS CONTROL MANTLE AND CORE
CONVECTION?
70
GRAND CHALLENGE 10. HOW ARE EARTHS INTERNAL
BOUNDARIES AFFECTED BY DYNAMICS?
Topography on three major Earth boundaries at and
beneath South America, showing the dominating
effects of subduction (Courtesy of N. Schmerr)
71
GRAND CHALLENGE 10. HOW ARE EARTHS INTERNAL
BOUNDARIES AFFECTED BY DYNAMICS?
Cross sections in a 3D seismic migration image of
S-wave reflectivity in the mantle wedge adjacent
to subducting Tonga slab quasihorizontal
structures not explained by standard petrological
models (Courtest of Y. Zheng)
72
GRAND CHALLENGE 10. HOW ARE EARTHS INTERNAL
BOUNDARIES AFFECTED BY DYNAMICS?
Migrated S-wave reflector images of the
core-mantle boundary (Courtesy of van der Hilst
et al.)
73
Sidebar 22 Core-Mantle Boundary Heat Flow
The transition from perovskite to
post-perovskite (uhh.you already heard about
this!) (Courtesy of Hernlund et al.)
74
GRAND CHALLENGE 10. HOW ARE EARTHS INTERNAL
BOUNDARIES AFFECTED BY DYNAMICS?
75

• SUSTAINING A HEALTHY FUTURE FOR SEISMOLOGY
• BUILDING AND SUSTAINING THE PROFESSIONAL
  PIPELINE
• ENHANCING ACCESS TO HIGH-PERFORMANCE COMPUTING
  CAPABILITIES
• SUSTAINING GLOBAL OBSERVATORIES
• ADVANCING PORTABLE INSTRUMENTATION
• CONTROLLED SEISMIC SOURCE SUPPORT
• PRODUCING ADVANCED SEISMOLOGICAL DATA PRODUCTS
• ENHANCING FREE AND OPEN ACESS TO DATA
• ADVANCES IN INSTRUMENTATION
• ENHANCED INTERDISCIPLINARY COOPERATION