David J Wald
!
Real-time seismology and
geospatial aspects earthquake
strong-ground motion,
amplification, intensity & loss
assessment.
-  Director: Earthquake Engineering
Research Institute
-  Director: Seismological Society of
America
-  Associate Editor: Earthquake
Spectra
-  Distinguished Lecturer, Earthquake
Engineering Research Institute
(2014-2015)
Sample Projects:
CISN ShakeMap : 6.7 km (4.2 mi) NW of American Canyon, CA
Aug 24, 2014 10:20:44 AM UTC M 6.0 N38.21 W122.32 Depth: 10.8km ID:72282711
M 6.0, 6.7 km (4.2 mi) NW of American Canyon, CA
Created: 18 minutes, 35 seconds after earthquake
Estimated Fatalities
•
•
•
Research, development & operations of real-time
information systems at the USGS National Earthquake
Information Center (NEIC), including “ShakeMap”, “Did
You Feel it?”, ShakeCast & PAGER.
Analyses of earthquake site effects and amplification.
Student projects: Geospatial (kriging) analysis of site
amplification, modeling secondary earthquake losses,
including landsliding & liquefaction, spatial variability.
Recent Publications:
PAGER
Version 2
Origin Time: Sun 2014-08-24 10:20:44 UTC (03:20:44 local)
o
o
Location: 38.21 N 122.32 W Depth: 10 km
39˚
Orange alert level for economic losses.
Significant damage is likely and the disaster is
potentially widespread. Estimated economic
losses are less than 1% of GDP of the United
States. Past events with this alert level have
required a regional or national level response.
Cloverdale
Roseville
Estimated Economic Losses
Green alert level for shaking-related fatalities.
There is a low likelihood of casualties.
Sacramento
38.5˚
Estimated Population Exposed to Earthquake Shaking
ESTIMATED POPULATION
EXPOSURE (k = x1000)
Santa Rosa
- -*
880k*
6,531k*
919k
Not felt
Weak
Light
Moderate
Very Strong
Severe
none
none
none
V. Light
Light
Moderate
Moderate/Heavy
Heavy
V. Heavy
none
none
none
Light
Moderate
374k
Moderate/Heavy
105k
Heavy
4k
V. Heavy
0
0
Violent
Extreme
V. Heavy
ESTIMATED MODIFIED
MERCALLI INTENSITY
Vacaville
PERCEIVED SHAKING
POTENTIAL
DAMAGE
Resistant
Structures
Vulnerable
Structures
Strong
*Estimated exposure only includes population within the map area.
Lodi
Vallejo
38˚
San Rafael
Population Exposure
population per ~1 sq. km from Landscan
Stockton
Structures:
Overall, the population in this region resides
in structures that are highly resistant to
earthquake shaking, though some vulnerable
structures exist.
Historical Earthquakes (with MMI levels):
San Francisco
Date
Dist. Mag.
Max
Shaking
(UTC)
(km)
MMI(#)
Deaths
1983-05-02 284 5.7
VIII(1k)
0
1980-01-24 76 5.8
VII(31k)
1
1989-10-18 132 6.9
IX(3k)
62
Recent earthquakes in this area have caused
secondary hazards such as landslides and
liquefaction that might have contributed to
losses.
Tracy
km
0
37.5˚
Fremont
50
Selected City Exposure
−123˚
from GeoNames.org
−122˚
MMI City
VII American Canyon
VII Napa
VII Suisun
VI Sonoma
VI Benicia
VI Fairfield
IV Sacramento
IV Stockton
IV San Francisco
IV Oakland
III Fremont
Map Version 2 Processed 2014−08−24 10:37:18 AM UTC
PERCEIVED
SHAKING
POTENTIAL
DAMAGE
Not felt
Weak
Light
Moderate Strong Very strong
Extreme
Mod./Heavy
Heavy
Very Heavy
none
none
none
Very light
PEAK ACC.(%g)
<0.1
0.5
2.4
6.7
83
>156
<0.07
0.4
1.9
5.8
11
22
43
83
>160
IV
V
VI
VII
VIII
IX
X+
13
Moderate
Violent
PEAK VEL.(cm/s)
INSTRUMENTAL
I
II−III
INTENSITY
Scale based upon Wald, et al.; 1999
Light
Severe
24
44
PAGER content is automatically generated, and only considers losses due to structural damage.
Limitations of input data, shaking estimates, and loss models may add uncertainty.
http://earthquake.usgs.gov/pager
bold cities appear on map
Population
19k
77k
28k
11k
27k
105k
466k
292k
805k
391k
214k
(k = x1000)
Event ID: nc72282711
Atkinson, G. M., C. B. Worden and D. J. Wald (2014). Intensity Prediction Equations for North
America, submitted to Bull. Seism. Soc. Am., 104(6), 3084-3093
Thompson, E. M., D. J. Wald, and C. B. Worden (2014). A Vs30 Map for California with Geologic
and Topographic Constraints, Bull. Seism. Soc. Am., 104 (5), 2313-2321.
Wald, D. J., K. Lin, L. Turner, and N. Bekiri, (2014), U.S. Geological Survey's ShakeCast SYSTEM:
A Cloud-based Future, Proc. Tenth National Conference on Earthquake Engineering (10NCEE),
Anchorage. 12 pp.