Ministry of Energy and Water Resources
Geological Survey of Israel
Simulation of Seismic-Wave Propagation through
Geometrically Complex Basins:
The Dead Sea Basin
Shahar Shani-Kadmiel
1,4
2
, Michael Tsesarsky ,
3
4
John N. Louie , and Zohar Gvirtzman
1 – Department of Geological and Environmental Sciences, Ben Gurion University
of the Negev, Beer-Sheva, Israel.
2 – Department of Structural Engineering, Ben Gurion University of the Negev,
Beer-Sheva, Israel.
3 – Nevada Seismological Laboratory University of Nevada, Reno, Nevada.
4 – Geological Survey of Israel, Jerusalem, Israel.
Prepared for the Steering Committee for Earthquake Readiness in Israel
Jerusalem, December 2012
Ministry of Energy and Water Resources
Geological Survey of Israel
Simulation of Seismic-Wave Propagation through
Geometrically Complex Basins:
The Dead Sea Basin
Shahar Shani-Kadmiel
1,4
2
, Michael Tsesarsky ,
3
4
John N. Louie , and Zohar Gvirtzman
1 – Department of Geological and Environmental Sciences, Ben Gurion University
of the Negev, Beer-Sheva, Israel.
2 – Department of Structural Engineering, Ben Gurion University of the Negev,
Beer-Sheva, Israel.
3 – Nevada Seismological Laboratory University of Nevada, Reno, Nevada.
4 – Geological Survey of Israel, Jerusalem, Israel.
Prepared for the Steering Committee for Earthquake Readiness in Israel
"‫במסגרת הפרויקט "איפיון סיכוני תנודות קרקע באגנים סדימנטריים בישראל‬
Jerusalem, December 2012
‫מדינת ישראל‬
‫משרד התשתיות הלאומיות‬
‫המכון הגיאולוגי‬
‫‪State of Israel‬‬
‫‪Ministry of National Infrastructures‬‬
‫‪Geological Survey‬‬
‫‪8.12.2012‬‬
‫תנודות קרקע באגני סדימנטריי בישראל‬
‫זהר גבירצמ‬
‫מניסיו שהצטבר בעול ידוע שבאגני גיאולוגיי צרי ועמוקי‪ ,‬שבנויי מסלעי רכי ביחס לשוליה‪ ,‬תנודות הקרקע בזמ רעידת‬
‫אדמה מתארכות ומתחזקות בשיעור ניכר‪ .‬אגני סדימנטריי עמוקי בישראל מפוזרי לאור בקע י המלח ועמקי הצפו‪ .‬בתחומי‬
‫האגני הסדימנטריי בישראל מצויי ריכוזי אוכלוסיה‪ ,‬בי היתר הערי בית שא וקריית שמונה‪ ,‬אזורי תעשיה ותיירות בדרו י‬
‫המלח‪ ,‬אזור תעשיה ומתקני רגישי בעמק זבולו ועוד‪.‬‬
‫יחד ע זאת‪ ,‬נכו להיו בישראל אי בידינו מדידות שמה נית לאפיי את התופעה ולכמתה‪ ,‬מפני שמאז הקמתה של מדינת ישראל‬
‫ובפרט מאז הצבת הרשת הסיסמית שלה לא התרחשו בישראל רעידות בינוניות או חזקות‪ .‬בנוס!‪ ,‬דלילותה היחסית של הרשת‬
‫הסיסמית בישראל‪ ,‬שכמעט ואינה כוללת תחנות באגני הסדימנטרי ‪ ,‬גורמת לכ שאפילו רישומי של רעידות חלשות כמעט לא‬
‫קיימי‪ .‬במצב זה אי אפשרות להשוות בי התנודות באגני לתנודות בשוליה ולא נית להערי את גודל התופעה והיקפה‪.‬‬
‫למחקר זה‪ ,‬שמתוכנ להימש מספר שני‪ ,‬הוגדרו שתי מטרות‪ :‬ראשית‪ ,‬לפרוס בכל אג סדימנטרי חשוב במדינת ישראל רשת סיסמית‬
‫ניידת שתרשו רעידות אדמה במש תקופה של כמה חודשי באתרי שוני באג ומחוצה לו‪ .‬שנית‪ ,‬לערו סימולציות נומריות של‬
‫אפקט האג ולכייל אות‪ ,‬במידת האפשר‪ ,‬על ידי המדידות שתיאספנה בהדרגה‪.‬‬
‫אנו מצפי לתרומה משמעותית בשלושה מישורי שכל אחד חשוב בפני עצמו‪ (1) .‬רישו הקלטות בו זמני של רעידות אדמה באגני‬
‫ובשוליה הסלעיי‪ (2) .‬פיתוח מתודולוגיה והבנה תיאורטית של אפקטי פני‪ %‬ובינ‪%‬אגניי‪ (3) .‬אפיו כמותי של ההגברה באגני‬
‫ישראל לצור עריכת תרחישי ולצור תקני בנייה‪.‬‬
‫בשני האחרונות הוקמה קבוצת מחקר בשיתו! פעולה בי ד"ר זהר גבירצמ מהמכו הגיאולוגי וד"ר מיכאל טסרסקי מאוניברסיטת‬
‫ב גוריו שבמסגרתה התקדמנו בתחו הסימולציות הנומריות של התפשטות גלי באגני סדימנטריי‪ .‬חלק ניכר מהמחקר נעשה על‬
‫ידי סטודנט לדוקטורט )שחר שני‪%‬קדמיאל( שנסע לפרופסור ג'ו לואי מהמעבדה הסיסמולוגי של נבדה בארה"ב ולמד ממנו כיצד‬
‫להשתמש בשתי תוכנות שפותחו במש שני רבות בארה"ב וכוילו במסגרת מחקרי רבי‪ .‬לאחר תקופת לימוד שבמהלכה בוצעו‬
‫סימולציות דו‪%‬מימדיות עבור אג י המלח במחשבי המעבדה הסיסמולוגית של נבדה‪ ,‬הגענו למצב שמאפשר לנו עצמאות חישובית‬
‫במכו הגיאולוגי‪.‬‬
‫המחקר שתואר לעיל מומ בחלקו מתקציב פרויקט רב שנתי של יציבות התשתית בי המלח וכ מכספי ועדת ההיגוי‪ .‬המאמר המצור!‬
‫בזאת מתו העיתו של החברה הסיסמולוגית אמריקנית מדגי תוצאות מסימולציות דו‪%‬ממדיות שערכנו לאג י המלח‪ .‬בשנה הבאה‬
‫אנו מתכנני להמשי במחקר תופעת מיקוד גיאומטרי של הגלי סיסמיי באגני כמו י המלח וכ לבצע סימולציות של עמק זבולו‪.‬‬
‫בכבוד רב‬
‫ד"ר זהר גבירצמ‬
‫ ‬
‫ ‬
‫ ‬
‫‪30 Malkhe Israel St.‬‬
‫‪95501 Jerusalem, Israel‬‬
‫‪Fax. 972-2-5380688‬‬
‫ ‬
‫ ‬
‫ ‬
‫ ‬
‫ ‬
‫רח' מלכי ישראל ‪30‬‬
‫ירושלים ‪ ,95501‬ישראל‬
‫‪Tel. 972-2-5314211‬‬
‫ ‬
‫ ‬
‫ ‬
‫ ‬
‫דר' זהר גבירצמן‬
‫ ‬
‫ ‬
‫ ‬
‫ ‬
‫‪Dr. Zohar Gvirtzman‬‬
‫‪02-5314269‬‬
‫‪[email protected]‬‬
Bulletin of the Seismological Society of America, Vol. 102, No. 4, pp. 1729–1739, August 2012, doi: 10.1785/0120110254
Simulation of Seismic-Wave Propagation through Geometrically
Complex Basins: The Dead Sea Basin
by Shahar Shani-Kadmiel, Michael Tsesarsky, John N. Louie, and Zohar Gvirtzman
Abstract The Dead Sea Transform (DST) is the source for some of the largest
earthquakes in the eastern Mediterranean. The seismic hazard presented by the DST
threatens the Israeli, Palestinian, and Jordanian populations alike. Several deep and
structurally complex sedimentary basins are associated with the DST. These basins are
up to 10 km deep and typically bounded by active fault zones.
The low seismicity of the DST, the sparse seismic network, and limited coverage
of sedimentary basins result in a critical knowledge gap. Therefore, it is necessary to
complement the limited instrumental data with synthetic data based on computational
modeling, in order to study the effects of earthquake ground motion in these sedimentary basins.
In this research we performed a 2D ground-motion analysis in the Dead Sea Basin
(DSB) using a finite-difference code. Cross sections transecting the DSB were compiled for wave propagation simulations. Results indicate a complex pattern of groundmotion amplification affected by the geometric features in the basin.
To distinguish between the individual contributions of each geometrical feature in
the basin, we developed a semiquantitative decomposition approach. This approach
enabled us to interpret the DSB results as follows: (1) Ground-motion amplification as
a result of resonance occurs basin-wide due to a high impedance contrast at the base of
the uppermost layer; (2) Steep faults generate a strong edge-effect that further amplifies ground motions; (3) Sub-basins cause geometrical focusing that may significantly
amplify ground motions; and (4) Salt diapirs diverge seismic energy and cause a decrease in ground-motion amplitude.
Introduction
Sedimentary basins are known to amplify ground motions and to prolong the shaking by trapping seismic energy
(Anderson et al., 1986; Joyner, 2000; Boore, 2004). The outcome of this phenomenon was observed in Mexico City
(Singh, Mena, and Castro, 1988), the Los Angeles basin
(Graves, Pitarka, and Somerville, 1998), and Kobe, Japan
(Pitarka et al., 1998), among other places. The Dead Sea
Basin (DSB) is a unique sedimentary basin due to its extreme
depth, nearly 10 km, subvertical boundary faults, and complex geometry formed by convex salt diapirs and concave
sub-basins. Several active faults within the basin provide
internal seismic sources in addition to external sources from
neighboring basins and the Dead Sea Transform (DST) itself.
These circumstances provide an opportunity to study the
influence of different intrabasin features on earthquake
ground motion. Our primary goal in this study is to develop
a semiquantitative methodology for decomposing a complex
basin effect to individual contributions derived from specific
geometrical features. Such an analysis enables better understanding of the integrated seismic phenomenon and allows
generalizations of semiquantitative rules, useful for other
basins around the world.
The second goal of this study is to model earthquake
ground motion in the DSB, which hosts important industrial
and tourist facilities in Israel, Jordan, and the Palestinian
Authority. The lack of seismic recordings in the basin, due to
relatively low seismicity of the region and relatively sparse
national seismic network, produces the need for synthetic data
in order to supplement the instrumental data. This study
explores principally the basin effects on earthquake ground
motion.
Geological Setting
The DST is one of the largest active strike-slip faults of the
world, connecting the east Anatolian fault in the north to the
extensional zone of the Red Sea in the south (Fig. 1a; Garfunkel, Zak, and Freund, 1981). It defines the active boundary
between the Arabian and the African plates with an estimated
ongoing slip rate of ∼3 to ∼5 mm=year (Wdowinski et al.,
1729
1730
S. Shani-Kadmiel, M. Tsesarsky, J. N. Louie, and Z. Gvirtzman
2004; Marco et al., 2005; Le Beon et al., 2008). The ∼105 km
of left-lateral motion along the DST since its formation in the
Early to Middle Miocene (Quennell, 1956; Freund, Zak, and
Garfunkel, 1968) has created several pull-apart basins, the largest being the DSB, 100 km × 20 km in size (Fig. 1b).
This study focuses on the DSB, which is bounded by
active normal step faults, filled with ∼10 km of soft sediments and penetrated by large salt diapirs. It is generally
accepted that both eastern and western boundary faults
(a) 32°
34°
(b)
36°
(Fig. 1b) and the normal step faults Sedom and Ghor-Safi
are active (Aldersons et al., 2003; Hofstetter et al., 2007;
Data and Resources).
Seismicity
Moderate and strong earthquakes associated with the
DST are evident in geological, historical, and archaeological
records. However, due to long return periods, the instrumental
35°18'
35°24'
35°30'
35°36'
Jericho
36°
200
F
CG
ean
31°36'
JLM
TLV
1927
32°
31°30'
Pla
Ara
31°24'
31°42'
31°36'
31°30'
31°24'
Mt. Massada
and plain
Cross-s ect ion A
31°18'
Di
31°18'
Li
dS
sa
n
Re
El Mazraa
Moun
tains
Hotels
31°06'
C ross-section B
Mt. Sedom
DSI
Moab
31°12'
Sedom Fault
ea
late
nP
ica
ap
ir
Afr
28°
bian
ELT
NBA
1995
Ein Gedi
te
AF
Sinai
M.
Shalem
AMN
BS
30°
Dragot
JV
ran
iter
Med Sea
Hotels
Ghor-Saf
i Fault
Easter n Boundary Fault
Jud
ea
100
DST
0
31°42'
31°48'
J eric
ho Fa u
lt
km
34°
Mou
ntai
ns
We
st e
rn B o
undary F ault
31°48'
31°12'
31°06'
DSI
31°00'
Amiaz plain
and sub-basin
Safi
31°00'
km
0
35°18'
Figure 1.
35°24'
35°30'
10
35°36'
(a) Overview map of the DST, compiled after Garfunkel, 1981. Arrows indicate directions of relative motion at faults.
Epicenters of the 1927 Jericho earthquake and 1995 Gulf of Aqaba earthquake marked by gray filled circles. (b) Shaded relief map based
on the DTM of Hall, 2008, overlaid by major faults and significant populated settlements, industrial facilities and tourist resorts. Modeled
cross sections and simulated sources are denoted by straight solid lines and stars, respectively. Faults modified after Bartov and Sagy, 1999;
Smit et al., 2008. Abbreviations: CGF, Carmel-Gilboa fault; DST, Dead Sea Transform; AF, Arava fault; JV, Jordan Valley; TLV, Tel-Aviv;
JLM, Jerusalem; AMN, Amman; BS, Beer-Sheva; ELT, Elat; NBA, Nuweiba; DSI, Dead Sea Industries. The color version of this figure is
available only in the electronic edition.
Simulation of Seismic-Wave Propagation through Geometrically Complex Basins: Dead Sea Basin
record is rather limited. To date, the strongest earthquake ever
recorded in Israel was the 1995 M w 7.2 Gulf of Aqaba earthquake (Fig. 1a), with its epicenter located ∼80 km south of
Elat, the southernmost city of the country (Hofstetter,
2003). Prior to that, the largest earthquake felt in the country
was the 1927 Jericho earthquake (Fig. 1a), later estimated
from damage reports as an M w 6.2 (Garfunkel et al., 1981;
Shapira, Avni, and Nur, 1993; Avni et al., 2002).
For seismic hazard assessment it has been suggested that
the DST is capable of producing earthquakes with magnitudes up to 7.5. Return periods for 7:5 ≥ M ≥ 5 were estimated as 50 years in the Elat area, 30 years in the Arava and
Dead Sea area, and 25 years in the Jordan Valley (Fig. 1a;
Shapira et al., 2007). However, because these estimates
strongly depend on the sparse historical record, much
research was invested in the unique paleoseismic record of
the Dead Sea lacustrine sediments.
Breccia beds in the Lisan formation formed during the
last 60,000 years were interpreted as seismites (Seilacher,
1984), induced by M > 5:5 earthquakes (Marco and Agnon,
1995; Marco et al., 1996; Marco and Agnon, 2005; Hamiel
et al., 2009). Marco et al. (1996) presented columnar sections
of the Lisan formation from the Massada plain and Amiaz
plain (Fig. 1b), exhibiting some 30 seismites that were formed
by the same set of earthquakes. The seismites found within the
Amiaz plain (Fig. 1b) are consistently thicker than those found
in the Massada plain, even though according to Begin et al.
(2005), 11 strong earthquakes from the recorded set occurred
just north of Massada, which is farther from the Amiaz plain.
Another indication of strong ground motion in the Amiaz
plain is presented by Levi et al. (2008), who studied the development of clastic dykes found in the Amiaz plain and
showed that they are seismically induced. According to Levi’s
models, a threshold value of M ≥ 6:5 earthquake at close
proximity is needed in order to achieve the injection velocities. Alternatively, the simulations presented here raise the
possibility that dyke injection as well as other seismites at
the Amiaz plain may be explained by exceptionally strong
ground-motion amplification.
The paleoseismic record of the Lisan formation shows
little evidence of surface ruptures that can be directly linked
with seismic activity on the boundary faults. Some superficial faulting is documented (Marco and Agnon, 1995; Marco
and Agnon, 2005) within the ductile sediments of the formation, however, these are localized features that have no continuous spatial distribution.
Simulation Methods
Modeling of basin response to wave propagation has
been used to study earthquake-shaking hazard in a limited
number of basins. Chaljub et al. (2010) have compared four
numerical predictions of ground motion in the Grenoble
Valley, France. The numerical modeling methods compared
were the arbitrary high-order derivative discontinuous Galerkin method (ADER-DGM; Käser, Dumbser, and de la Puente,
1731
2006), the spectral-element method (SEM; Chaljub et al.,
2005), the finite-difference method (FDM; Kristek, Moczo,
and Pazak, 2009) and another implementation of the SEM
(Stupazzini, Paolucci, and Igel, 2009). These three methods,
together with the finite-element method (FEM), are at present
the most powerful numerical modeling methods for earthquake ground motion (Chaljub et al., 2010). They concluded
that no single numerical modeling method can be considered
as the best for all important medium wave-field configurations in both computational efficiency and accuracy.
Our modeling employs the FDM code E3D that was
developed by the Lawrence Livermore National Laboratory
(Larsen et al., 2001). E3D is listed by the Organization for
Economic Cooperation and Development’s Nuclear Energy
Agency (see Data and Resources). The E3D software
simulates wave propagation by solving the elastodynamic
formulation of the full wave equation on a staggered grid.
The solution scheme is fourth-order accurate in space and
second-order accurate in time (Larsen et al., 2001). In this
research we employ the software in 2D mode. Although 2D
mode does not allow us to model truly closed basins, a clear
benefit of 2D analysis is that it allows modeling of higher
frequencies.
Model Setup
Two geological cross sections were simulated in this
study (locations in Fig. 1b): cross-section A transects the
basin east of Mount Massada, a UNESCO world heritage
site (Fig. 2a); cross-section B transects Mount Sedom and
the Amiaz plain near the Ein-Bokek Hotel complexes and
the industrial facility of the Dead Sea Industries (Fig. 2b).
The cross sections were constructed based on a compilation
of available geological data, borehole data, for example,
Sedom deep 1 (Baker, 1994), and geophysical data, mainly
seismic and gravimetry surveys (ten Brink et al., 1993;
Al-Zoubi and ten Brink, 2001).
For cross-section A, we used structural maps of the top
and bottom of the Sedom formation salt unit (Al-Zoubi and
ten Brink, 2001) and a generalized north–south cross section
of the entire basin (Sagy, 2009) and used it for correlation
with cross-section B. Cross-section B was compiled based
on structure from seismic surveys and supplemented by borehole data for mechanical properties, specifically, pressurewave velocity and density (Frieslander, 1993; Baker, 1994;
Al-Zoubi, Shulman, and Ben-Avraham, 2002). Mechanical
properties such as shear-wave velocity and quality factors
were derived using empirical relations presented in Brocher
(2008). The salt diapir in section B protrudes through the
uppermost Lisan formation and gives rise to Mount Sedom,
rising ∼225 m above the Dead Sea and ∼100 m above the
Amiaz plain. Thus, the Amiaz plain is bounded by the western boundary fault in the west and Mount Sedom in the east
and is actually a sub-basin within the DSB.
To simplify the numerical calculations in E3D, the topography of the cross section was flattened; the top surface of the
1732
1.0
0.8
0.6
0.4
1
0.2
0.0
10
8
6
4
4
2
0
Mt. Massada and
Massada plain
(f)
Massada
Reference
1
4
4
(g)
2
3
Amiaz plain and
sub-basin
Mt. Sedom
W
km/s
SSD
LSD
5
GSF
EBF
GSF
15
0
3
SF
WBF
SF
10
(i)
5
18
5
m/s
3
0.1
Time, s
5
10
0.0
6
6
6
15
}
1
Frequency, Hz
6
−0.1
20
0
(e)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
(j)
7
Shear wave velocity
E
Horizontal ground
velocity
(h)
m/s
7
0.4
2
0.3
3
0.2
4
5
0.1
6
Spectral velocity
E
WBF
Depth, km
2
4
W
(d)
4
3
0
(c)
Amiaz
Reference
EBF
(b)
Amp. ratio
(a)
PGV, m/s
S. Shani-Kadmiel, M. Tsesarsky, J. N. Louie, and Z. Gvirtzman
0.0
7
0
5
10
15
20
25
0
5
Distance east, km
10
15
20
25
Distance east, km
Lisan and Samra Fm. - Pleistocene
Hazeva Formation - Miocene
Amora Formation - Pleistocene
Mesozoic
Sedom Formation - Pliocene
Paleozoic
Basement
Figure 2. Dead Sea Basin simulation results: Left panel cross-section A (Massada) and Right panel cross-section B (Amiaz). (a, f) Horizontal PGV. (b, g) Amplification ratio relative to a reference model. (c, h) Shear-wave velocity model of the modeled cross section.
(d, i) Time-distance plot of horizontal velocity from surface cells. Gray is no ground motion, black is positive (east) ground motion,
and white is negative (west) ground motion. Scale saturates at 0:1 m=s for clarity. (e, j) Frequency-distance plot, computed as the Fourier
spectra of the synthetic seismograms presented in (d, i). The scale saturates at 0:4 m=s for clarity. Abbreviations: WBF, western boundary
fault; EBF, eastern boundary fault; SF, Sedom fault; GSF, Ghor-Safi fault; SSD, Sedom Salt diapir; LSD, Lisan Salt diapir. The color version of
this figure is available only in the electronic edition.
resulting model conforms to the average elevation of the exposed Lisan formation along the transecting line. The Lisan
formation is the top most sediment filling the basin and is at an
average elevation of −370 m ( below sea level) along crosssection A and −260 m along cross-section B. The water of the
Dead Sea and the air surrounding it was replaced with Lisan
formation sediments to fill the missing topography. Mount
Sedom above the Sedom Salt diapir (−180 m) was totally removed, as well as the slopes of the Judea Mountains and the
Moab Mountains to the west and east of the Dead Sea, respectively (Fig. 1b). Therefore, the results of our simulations
should only be applied to the basin itself and not to its unreal
boundaries, which might have a topographic effect that was
not considered. Water effects within the lake, such as waterbottom multiple reflections, were also ignored.
As part of the simulation preprocessing, the geological
cross sections were spatially discretized into the intended grid
spacing, depending on the modeled frequencies. Simulation
Simulation of Seismic-Wave Propagation through Geometrically Complex Basins: Dead Sea Basin
Table 1
Dead Sea Basin, 2D Simulation Parameters
Model dimensions (km; grid cells)
Spatial discretization (km)
Time steps (#)
Time step interval (s)
Modeled time (s)
Simulation processor time (hours)
Minimum; maximum V P (km=s)
Minimum; maximum V S (km=s)
Minimum; maximum density (g=cm3 )
Minimum; maximum QP
Minimum; maximum QS
26:74 × 15; 5348 × 3000
0.005
40,000
0.0005
20.0
∼30
1.35; 5.94
0.41; 3.55
1.74; 2.70
46; 806
23; 403
parameters and mechanical properties of the geological units
are summarized in Tables 1 and 2, respectively.
The simulated scenario presented here (Fig. 2) is a normal-slip rupture initiating at a depth of 13 km on Sedom fault
near the lower limit of the seismogenic zone in the region
(Aldersons et al., 2003; Ambraseys, 2006). In our simulations the source is described in terms of a finite-length fault
with uniform moment. The modeled hypocenter is denoted
by a star and paired arrows pointing in the slip direction. The
ruptured fault plane of the finite source extends 3.5 km in the
up-dip direction, and rupture initiates near the bottom (of the
fault plane). For our parametric study of basin effects we kept
simple ruptures entirely within high velocity rocks below the
basin. The normal-faulting double-couple rupture front propagates radially from the hypocenter along the fault plane, at
a constant rupture velocity of 2:8 km=s (Scholz, 2002). All
the 2D elements on the fault plane were given identical moment and a Gaussian source time function with frequency
content between 0.1 and 10 Hz. Note that the size of the
source (i.e., its moment) is not important in this 2D analysis
that allows no energy to dissipate in the third dimension.
Therefore, we only analyze the relative amplification and
derive no conclusions from the absolute ground motion.
Simulation Results
Simulation results of the modeled cross-sections A and
B are summarized and visualized in Figure 2a–j by panels for
each cross section. From top to bottom they present:
1733
Figure 2a,f: Horizontal peak ground velocity (PGV)
across the modeled section sampled at model resolution (absolute value).
Figure 2b,g: Amplification ratio across the modeled section computed relative to a reference model, which is a
homogeneous medium with properties of the surrounding
rocks. Note that this presentation of amplification following
Gvirtzman and Louie (2010), differs from the common way
of presenting amplification relative to reference stations on
hard rock at the basin edges.
Figure 2c,h: The modeled cross section, shaded according to shear-wave velocities (listed in Table 2).
Figure 2d,i: Time-distance plot of horizontal velocity
synthetic seismograms sampled at the surface cells. Gray
is no ground motion, black is positive (east) ground motion,
and white is negative (west) ground motion. Although PGVs
reached values of nearly 1 m=s, the scale saturates at 0:1 m=s
for clarity.
Figure 2e,j: Frequency-distance plot, computed as the
Fourier spectra of the synthetic seismograms presented in
Figure 2d,i. The scale saturates at 0:4 m=s for clarity.
Description of Results
The largest ground motions are found directly above the
source in both the reference and the modeled cross sections
(observation 1 in Fig. 2a,f). Ground-motion amplification
however, increases toward the side of the basin opposite
the source (observation 2 in Fig. 2b,g). In both sections a
local minimum appears approximately at the same location
regardless of diapir or fault location (observation 3 in
Fig. 2b,g). In both sections strong ground-motion amplification is observed near faults and subvertical boundaries of salt
bodies (observation 4). The time-distance plots (panels d and
i) show that waves traveling through the Lisan and Sedom
Salt diapirs reach the surface faster than waves traveling
through the surrounding geological units (observation 5).
It is also noticeable that the western and eastern boundary
faults act as strong reflectors channeling most of the seismic
energy into the basin (observation 6). The frequencydistance plots (panels e and j) reveal resonance patterns (observation 7) at the fundamental frequency f 0 V S =4h, in
Table 2
Velocity, Density, and Q Properties of the Dead Sea Basin Formations*
Geological Unit
V P , km=s
V S , km=s
ρ, g=cm3
QP
QS
Lisan & Samra formations—Pleistocene
Amora formation (upper)—Pleistocene
Amora formation (lower)—Pleistocene
Sedom formation—Pliocene
Hazeva formation—Miocene
Mesozoic
Paleozoic
Basement
1.35
3.75
4.04
4.18
4.53
4.81
5.58
5.94
0.41
2.20
2.44
2.54
2.78
2.95
3.37
3.55
1.74
2.25
2.28
2.15
2.39
2.47
2.62
2.70
46
356
414
440
510
564
726
806
23
178
207
220
255
282
363
403
*V P and ρ were measured in Sedom deep 1 borehole, V S , QP and QS were calculated using
empirical relations (Frieslander, 1993; Baker, 1994; Brocher, 2008).
1734
S. Shani-Kadmiel, M. Tsesarsky, J. N. Louie, and Z. Gvirtzman
accordance with the shear-wave velocity and thickness of the
model’s uppermost layer. In cross-section A, overtones at
fn nf 0 , n 1, 3,5,7,…, are visible directly above the
source. In cross-section B the overtones are absent above
the salt diapir but appear on both sides. The calculated frequencies for vertical resonance in the Amiaz sub-basin
bounded by the western boundary fault and the salt diapir
(Fig. 2b), are ∼0:3, ∼0:9, ∼1:5, and ∼2:1 Hz for modes 1,
2, 3, and 4, respectively, which correspond to the values
marked as observation 7 in Figure 2b.
Model Decomposition
The results described previously reflect a complex interaction of several effects contributed by the various geometric
features in the basin. To gain an in-depth understanding of
this phenomenon that will enable the interpretation of the
general amplification trend and the local minima and maxima, a geometrical decomposition method is devised in the
following list. Six different geometrical models were constructed and analyzed. The complexity of the models successively evolved, changing only one element at a time. Figure 3
shows the step-by-step evolution of the six models used as
simulation input. The following is a short description of the
different models:
Figure 3a, reference: A reference model with a single
homogeneous medium.
Figure 3b, layers: A series of horizontal sedimentary
layers with mechanical properties of the DSB geological units.
Figure 3c, faults: A series of layers as in (b) bounded by
two near-vertical faults.
Figure 3d, diapir: A series of layers as in (b) with a
dome-shaped intrusion (diapir), near the surface.
Figure 3e, basin: A series of layers as in (b) with a deep
sub-basin near the surface.
Figure 3f, combined: A model combining all of the features in Figure 3a–e.
The mechanical properties of the individual units are
summarized in Table 2. The modeled earthquake hypocenter
is fixed at the same location in all simulations (see Fig. 3).
Fault plane of the finite source extends 3.0 km in the upward
dip direction and rupture initiates near the bottom (of the
fault plane). The normal-faulting double-couple rupture front
propagates radially from the hypocenter along the fault
plane, at a constant rupture velocity of 2:8 km=s (Scholz,
2002). All the 2D elements on the fault plane were given
identical moment and a Gaussian source time function.
Table 3 summarizes the simulation parameters.
Decomposition Results
The PGV signature of the feference model is straightforward. Strongest ground motions above the source and a gradual decrease with distance (observation 1 in Fig. 3a). The
layers model produces a ground-motion amplification above
the source (observation 1 in Fig. 3b) and the amplification
signature follows a trend similar to that presented in Figure 2
(observation 2 in Fig. 3b). At a distance of approximately
15 km a local minimum appears, substantiating that this phenomenon is independent of intrabasin features, that is, faults
and diapirs which are absent from this model (observation 3).
In the faults model, ground-motion amplification increases
near the basin boundary faults or edges (observations 4
and 5 in Fig. 3c). The asymmetry between the two edgeeffects in opposite sides of the basin is probably related to
the general trend of the ground-motion amplification that increases toward the right side of the basin (observation 2). The
PGV signature produced by the diapir model resembles that
of the Layers model except for a small depression directly
above the diapir (observation 6 in Fig. 3d). The basin model
produces three distinct peaks above the sub-basin, observations 7, 8, and 9 in Figure 3e. Combining all the geometrical
features into a single model, the resulting signal contains the
individual signature of each feature (Fig. 3f).
Interpretation
Our decomposition technique revealed that the general
trend (observation 2) of the ground-motion amplification and
the local minimum (observation 3) are both independent of
intrabasin features. The general trend in the amplification ratio reflects the fact that PGV of the reference model decays
over a much shorter distance compared with that of the layers
model. While in the reference model PGV at a distance of
more than 15 km from the epicenter decays to nearly zero,
in the layers model energy is trapped in the uppermost layer
and PGV remains approximately constant (Fig. 3b).
Entrapment of seismic energy in a soft layer on top of a
hard substrate is a well-known phenomenon, visualized by
the wave-field snapshots in Figure 4. This effect is caused
by interference of seismic waves in several different manners: (1) Body waves reflected from the surface interfere with
body waves reflected from the base of the uppermost layer
causing vertical resonance; (2) Body and surface waves interaction caused when body waves reflected from the base of
the uppermost layer interfere with surface waves traveling
across the basin; and (3) Surface-surface waves interaction
caused when left-traveling surface waves interfere with righttraveling surface waves. The net result of the previously described processes is significant ground motion for prolonged
duration.
The local minimum within the generally increasing
amplification trend is related to the source radiation pattern.
It resides roughly on a plane rotated at 45° to the nodal planes
and is visible in the time-distance plots in Figures 2 and 3b
(observation 3) as the first motion of shear-waves transform
from left to right.
The ground-motion amplification that occurs near the
boundary faults of the basin is caused by the interference
of surface waves and body waves to create an edge-effect
(Kawase, 1996; Graves et al., 1998; Pitarka et al., 1998). At
Simulation of Seismic-Wave Propagation through Geometrically Complex Basins: Dead Sea Basin
Freq., Hz
Time, s
Depth, km
Amp.
ratio
PGV, m/s
(a)
(b)
1.2
0.8
0.4
0.0
8
6
4
2
0
0
PGV, m/s
Amp.
ratio
Depth, km
2
3
5
1
4
5
10
15
0
5
10
15
20
0
003
003
4
3
SW
5
RW
BW
2
4
6
5 10 15 20 25 30 35 0
Distance, km
Time, s
(c)
1
0
Freq., Hz
1735
5 10 15 20 25 30 35 0
Distance, km
(d)
5 10 15 20 25 30 35
Distance, km
(e)
(f)
1.2
0.8
0.4
0.0
8
6
4
2
0
0
7
6
8
9
4
6
7
8
5
5
10
15
0
5
10
15
20
0
2
4
6
0
5 10 15 20 25 30 35 0
Distance, km
5 10 15 20 25 30 35 0
Distance, km
Distance, km
km/s
0
1
2
3
Shear wave velocity
5 10 15 20 25 30 35
m/s
−0.1
0.0
0.1
Horizontal ground velocity
m/s
0.0 0.2 0.4 0.6 0.8
Spectral velocity
Figure 3. Simulation results from six models: (a) reference, (b) layers, (c) faults, (d) diapir, (e) basin, and (f) combined. The presentation
scheme follows that of Figure 2. Time-distance plot scale saturates at 0:1 m=s, and the frequency-distance plot scale saturates at 0:8 m=s for
clarity. Abbreviations: PGV, peak ground velocity; Amp., amplification; Freq., frequency; BW, body wave; SW, surface wave; RW, reflected
wave. The color version of this figure is available only in the electronic edition.
1736
S. Shani-Kadmiel, M. Tsesarsky, J. N. Louie, and Z. Gvirtzman
Table 3
Model Decomposition Simulation Parameters
35 × 15; 1750 × 750
0.02
10,000
0.002
20.0
∼24
1.35; 5.94
0.41; 3.55
1.74; 2.70
46; 806
23; 403
Model dimensions (km; grid cells)
Spatial discretization (km)
Time steps (#)
Time step interval (s)
Modeled time (s)
Simulation processor time (hours)
Minimum; maximum V P (km=s)
Minimum; maximum V S (km=s)
Minimum; maximum density (g=cm3 )
Minimum; maximum QP
Minimum; maximum QS
the near fault (the fault nearest the source), seismic waves
propagate upward on both sides of the fault, the faster traveling body waves on the left side of the fault reach the surface
before the slower body waves propagating on the right side
of the fault. Surface waves formed at the basin edge propagate into the basin and interfere with later arriving body
waves (Gvirtzman and Louie, 2010). The development of
this near-fault edge-effect (observation 4) is visualized in
the time-distance plot of the faults model in Figure 3c (body
waves, BW; surface waves, SW). At the far fault (on the right
side of the basin), seismic waves reflected by the fault interfere with seismic waves trapped in the uppermost layer resulting in a similar edge-effect (observation 5 in Fig. 3c). The
time-distance plot of the faults model shows the development
in time of the far-fault edge-effect (reflected waves, RW).
The diapir, an upward convex structure with shear-wave
velocity higher than its surroundings, leads to a decrease in
ground-motion amplification (observation 6 in Fig. 3d). We
lt
Eastern Boundary Fault
Ghor-S
afi Fa
ult
ndary Fau
lt
t=2.0 s
lt
Sedom Fau
Western Bou
ndary Fau
lt
Sedom Fau
Western Bou
Ghor-S
afi Fa
ult
Sedom
Salt
Diapir
Eastern Boundary Fault
Sedom
Salt
Diapir
propose that this convex body scatters body waves that are
reflected downward from the surface thus, preventing vertical resonance.
The two peaks above the edges of the sub-basin in
Figure 3e marked as observations 7 and 9 are near and far
edge-effects, respectively, caused by the subvertical walls
bounding the sub-basin. The central peak, observation 8, is
caused by a geometrical convergence of the seismic waves
by the concave structure of the sub-basin (Graves et al.,
1998; Semblat et al., 2002). We term this type of convergence “geometrical focusing”.
Figure 5 presents PGV curves (Fig. 5a) and amplification
ratios (Fig. 5b) from all six simulations plotted together
above the combined model (Fig. 5d) for comparison. After
analyzing the individual signatures of the geometrical features, we are able to quantify their relative contribution. In
particular, we distinguish between ground-motion amplification related to material properties such as that illustrated by
the layers model, and ground-motion amplification related to
geometrical features such as that illustrated by the faults,
diapir, and sub-basin models.
To accomplish this, the amplification ratio for the combined model is computed relative to the layers model and
presented in Figure 5c. This exercise demonstrates that
material related ground-motion amplification is perturbed by
geometrical effects. Fault-related edge effect amplifies
ground motion by 30% (observations 4 and 5); geometrical
focusing in sub-basins amplifies ground motion by 30%
(observation 8); and divergence of seismic waves by diapirs
deamplifies ground motion by 50% (observation 6). As some
of the seismic energy is trapped in the sub-basins, ground
motion between the sub-basin and the far-fault is deamplified
by 30% (observation 10).
t=3.5 s
Sedom
Salt
Diapir
t=4.6 s
Sedom
Salt
Diapir
t=5.2 s
Sedom
Salt
Diapir
t=6.8 s
Sedom
Salt
Diapir
t=10 s
Figure 4. Wave-field snapshots of modeled cross-section B.
White is motion east; black is motion west. Time in seconds is displayed at the bottom right corner of each snapshot. The color version of this figure is available only in the electronic edition.
Discussion
The decomposition process presented here not only
enables us to identify the individual contribution of various
intrabasin features to the ground-motion amplification, it
also allows us to reexamine the complex results of the
DSB simulations.
Material related ground-motion amplification occurs
throughout the entire basin due to resonance developed
within the Pleistocene lacustrine sediments of the Samra
and Lisan formations (unified in our models). This effect is
caused by the impedance ratio across the interface between
the Samra–Lisan formation and the sediments of the Pleistocene Amora formation and the Pliocene Sedom salt, which
are 3.5 and 4, respectively. Material related ground-motion
amplification is illustrated by the simulation results of the
layers model (Fig. 3b), of which material properties follow
those of the geological units of the DSB cross sections.
Figure 6a presents synthetic seismograms sampled from
the reference and the layers models (see Fig. 3a,b for location). The Fourier spectra of these seismograms (Fig. 6b) and
the spectral amplification ratio (Fig. 6c), reveal amplification
Simulation of Seismic-Wave Propagation through Geometrically Complex Basins: Dead Sea Basin
0.0
8
8
7
Velocity, m/s
0.4
(a)
0.4
0.0
−0.4
Reference
Layers
−0.8
5
6
0
10
12
14
16
18
km/s
5
10
15
10
15
20
25
30
35
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Distance, km
Figure 5.
PGV data from all six simulations plotted together:
(a) PGV across the modeled section. (b) Amplification ratio relative
to the reference model. (c) Amplification ratio of the combined
model relative to the layers model. (d) Shear velocity model of
the combined model. Line thickness varies so that overlapped lines
remain visible. The color version of this figure is available only in
the electronic edition.
at the fundamental frequency of 0.2 Hz, and at its overtones
0.6, 1.0, and 1.4 Hz.
Comparing the synthetic seismogram from the idealized
layers model with that from the Amiaz plain in cross-section
B of the DSB simulations (see Fig. 2b for location) shows that
the typical resonance pattern of mode 1, 2, 3 is distorted by
ground-motion amplification at other frequencies as well
(labeled in Fig. 7 with a question mark). Specifically, note
the prominent peak found between the fundamental frequency, 0.3 Hz, and the first overtone, 0.9 Hz. We suggest
that these amplified frequencies are contributed by the basin
deeper structure.
In light of these results we suggest an explanation to the
abundance of clastic dykes injected into the Lisan formation
in the Amiaz plain (Levi et al., 2008). Whereas seismites,
that is, breccia, liquefied layers, and slumps, have been
observed throughout the Lisan formation, the clastic dykes
are confined to the Amiaz plain above the Amiaz sub-basin.
Emplacement of clastic dykes compared with other seismites
requires a higher energy threshold. We attribute the localization of clastic dykes to the previously described geometrical
effect of the Amiaz sub-basin.
The topographic effect on ground-motion amplification
was not accounted for in our simulations; however, with the
results of Boore (1972) this effect can be readily estimated.
Within the DSB, the sole prominent topographic feature is
0.002
0.001
0.1 0.2 0.5 1
2
mode 2
mode 3
mode 4
0.02
0.01
0.005
8
6
4
2
0
0.1 0.2 0.5 1
5 10
Frequency, Hz
2
5 10
Frequency, Hz
Figure 6. (a) Synthetic seismograms of horizontal ground velocity sampled from the reference model and the layers model (see
Fig. 4a,b for location). (b) Fourier spectrum of each of the synthetic
seismograms. (c) Spectral amplification ratio.
Mount Sedom, with a cross-sectional wavelength of 4 km
and a shear-wave velocity of 2:54 km=s. Because topography can have significant effects on seismic waves when
the incident wavelength is comparable to the size of the topographic feature, amplification would be expected at
∼0:6 Hz (Boore, 1972). The steep shoulders of the DSB rise
400 to 500 m above the basin with shear-wave velocity
ranging from 2.95 to 3:37 km=s. To assess the topographic
effect of these features, we follow the method presented by
(a)
0.2
0.
0.0
0.
−0.2
−0.
Reference
Amiaz
−0.4
−0.
0
2
4
6
8
10
12
14
16
18
Time, s
(b)
(c)
1
0.5
10
0.2
0.1
0.05
0.02
0.01
0.005
0.002
0.001
8
6
4
?
mode 2
mode 3
mode 4
10
0.2
0.1
0.05
mode 1
5
mode 1
8
10
Amplification ratio
7
(c)
1
0.5
6
5
8
(b)
9 10
3
4
0
6
Time, s
6
0
2.0
1.6
1.2
0.8
0.4
0.0
0
4
Amplification ratio
1
2
2
4
Velocity, m/s
4
Velocity, m/s
Depth, km
(d)
0.8
}
Amp. ratio
(c)
Reference
Layers
Faults
Diapir
Basin
Combined
1
Velocity, m/s
Amp. ratio
(b)
1.2
Shear wave velocity
PGV, m/s
(a)
1737
2
0
0.1 0.2 0.5 1
2
5 10
Frequency, Hz
0.1 0.2 0.5 1
2
5 10
Frequency, Hz
Figure 7. (a) Synthetic seismograms of horizontal ground velocity sampled from the cross-section A and its reference model (see
Fig. 2b for location). (b) Fourier spectrum of each of the synthetic
seismograms. (c) Spectral amplification ratio.
1738
S. Shani-Kadmiel, M. Tsesarsky, J. N. Louie, and Z. Gvirtzman
Ashford et al. (1997), yielding topographic amplification at
∼0:65 Hz. Our study explores the ground-motion effects of
basin structure between 0.1 and 7 Hz, hence, our results are
limited at the lower end of this frequency band, where topographic effects are expected to occur.
Water-bottom multiple reflections in the Dead Sea
would be expected to affect the vertical resonance discussed
previously. The density of the briny Dead Sea water is
∼1:2 g=cm3 , hence, pressure-wave velocity is slightly higher
than 1:5 km=s, and the fundamental resonant frequency for a
water column of 200 m is on the order of 1.9 Hz. Our models,
which substitute shallow sediments for lake water, do not
show this pressure-wave resonance.
Summary and Conclusions
The dimensions of the Dead Sea Basin (DSB), 10 km
deep × 20 km wide × 100 km long, its steep boundary faults
and salt diapir intrusions result in a complex geometry. Due
to the low seismicity of the Dead Sea Transform (DST) combined with limited instrumental coverage of the DSB, there is
a critical knowledge gap in terms of expected ground motions during a strong earthquake. However, moderate and
large seismic events from instrumental (Data and Resources),
archaeological and historical (Ellenblum et al., 1998), and
geological (Marco et al., 1996; Levi et al., 2008) records
are well documented. In this research we performed a 2D numerical ground-motion analysis of the DSB with particular
consideration of the geometrical complexity. Specifically,
we studied the individual contribution of each geometrical
feature in the basin to surface ground motion.
We show that via a semiquantitative decomposition
approach, the contribution of the individual intrabasin features to ground motion can be identified in an otherwise complex signal. This process not only allows identification of the
individual signature of each feature, but also conveys a physical understanding of how these signatures interact to form
the complete signal. Ground-motion amplification in geometrically complex sedimentary basins occurs (1) basin-wide
due to resonance and anelastic effects, (2) above steep structures, that is, faults and diapir flanks due to an edgeeffect, and (3) above sub-basins due to localized geometrical
focusing. Narrow and upward convex bodies with a relatively
high seismic-wave velocity, such as salt diapirs and magmatic
intrusions, may cancel ground-motion amplification.
Data and Resources
Description of E3D is available from http://www
.oecd‑nea.org/tools/abstract/detail/ests1300 (last accessed
December 2011). The Earthquake Catalog of the Geophysical Institute of Israel can be found at www.gii.co.il (last
accessed December 2011). Data on the digital terrain
model of Israel (Hall, 2008) were retrieved from www
.sciencefromisrael.com/index/914317320tx22207.pdf (last
accessed December_2011).
Acknowledgments
This research was partially funded by the Ministry of National Infrastructures of the State of Israel, Grant #210-17-001, and by the Geological
Survey of Israel as part of a project assessing the instability factors in the
Dead Sea Infrastructure.
References
Al-Zoubi, A., and U. S. ten Brink (2001). Salt diapirs in the Dead Sea basin
and their relationship to Quaternary extensional tectonics, Mar. Petrol.
Geol. 18, no. 7, 779–797.
Al-Zoubi, A., H. Shulman, and Z. Ben-Avraham (2002). Seismic reflection
profiles across the southern Dead Sea basin, Tectonophysics 346,
no. 1–2, 61–69, doi 10.1016/S0040-1951(01)00228-1.
Aldersons, F., Z. Ben-Avraham, A. Hofstetter, E. Kissling, and T. Al-Yazjeen
(2003). Lower-crustal strength under the Dead Sea basin from local
earthquake data and rheological modeling, Earth Planet. Sci. Lett.
214, no. 1–2, 129–142, doi 10.1016/S0012-821X(03)00381-9.
Ambraseys, N. N. (2006). Comparison of frequency of occurrence of earthquakes with slip rates from long-term seismicity data: The cases of
Gulf of Corinth, Sea of Marmara and Dead Sea fault zone, Geophys.
J. Int. 165, no. 2, 516–526, doi 10.1111/j.1365-246X.2006.02858.x.
Anderson, J. G., P. Bodin, J. N. Brune, J. Prince, S. K. Singh, R. Quaas, and
M. Onate (1986). Strong ground motion from the Michoacan, Mexico,
earthquake, Science 233, no. 4768, 1043–1049.
Ashford, S. A., N. Sitar, J. Lysmer, and N. Deng (1997). Topographic effects
on the seismic response of steep slopes, Bull. Seismol. Soc. Am. 87,
no. 3, 701–709.
Avni, R., D. Bowman, A. Shapira, and A. Nur (2002). Erroneous interpretation of historical documents related to the epicenter of the 1927 Jericho
earthquake in the Holy Land, J. Seismol. 6, no. 4, 469–476.
Baker, S. (1994). Sedom Deep #1, Geological Completion Report, The Israel
National Oil Co. Ltd, Geol. Surv. Israel.
Bartov, Y., and A. Sagy (1999). Late Pleistocene extension and strike-slip in
the Dead Sea basin, Geol. Mag. 141, no. 5, 565–572, doi 10.1017/
S001675680400963X.
Begin, Z. B., J. N. Louie, S. Marco, and Z. Ben-Avraham (2005). Prehistoric
seismic basin effects in the Dead Sea pull-apart, The Ministry of National Infrastructures, Geol. Surv. Israel, Report GSI/04/05.
Boore, D. M. (1972). A note on the effect of simple topography on seismic
SH waves, Bull. Seismol. Soc. Am. 62, no. 1, 275–284.
Boore, D. M. (2004). Can site response be predicted? J. Earthquake Eng. 8,
no. 1, 1–41.
Brocher, T. (2008). Key elements of regional seismic velocity models for
long period ground motion simulations, J. Seismol. 12, no. 2, 217–
221, doi 10.1007/s10950-007-9061-3.
Chaljub, E., C. Cornou, P. Guéguen, M. Causse, and D. Komatitsch (2005).
Spectral-element modeling of 3D wave propagation in the Alpine
Valley of Grenoble, France, in Proc. from Geophysical Research
Abstracts, Wien, Austria, vol. 7, 05225
Chaljub, E., P. Moczo, S. Tsuno, P. Y. Bard, J. Kristek, M. Käser,
M. Stupazzini, and M. Kristekova (2010). Quantitative comparison
of four numerical predictions of 3D ground motion in the Grenoble
Valley, France, Bull. Seismol. Soc. Am. 100, no. 4, 1427–1455, doi
10.1785/0120090052.
Ellenblum, R., S. Marco, A. Agnon, T. Rockwell, and A. Boas (1998).
Crusader castle torn apart by earthquake at dawn, 20 May 1202,
Geology 26, no. 4, 303–306.
Freund, R., I. Zak, and Z. Garfunkel (1968). Age and rate of the sinistral
movement along the Dead Sea Rift, Nature 220, no. 5164, 253–
255, doi 10.1038/220253a0.
Frieslander, U. (1993). Velocity survey, Sedom Deep-1 Well: Israel Petroleum Research of Geophysics Report, 849, no. 297, 92.
Garfunkel, Z., I. Zak, and R. Freund (1981). Active faulting in the Dead Sea
rift, Tectonophysics 80, no. 1–4, 1–26, doi 10.1016/0040-1951(81)
90139-6.
Simulation of Seismic-Wave Propagation through Geometrically Complex Basins: Dead Sea Basin
Graves, R. W., A. Pitarka, and P. G. Somerville (1998). Ground-motion amplification in the Santa Monica area: Effects of shallow basin-edge
structure, Bull. Seismol. Soc. Am. 88, no. 5, 1224–1242.
Gvirtzman, Z., and J. N. Louie (2010). 2D analysis of earthquake ground
motion in Haifa Bay, Israel, Bull. Seismol. Soc. Am. 100, no. 2,
733–750.
Hall, J. K. (2008). The 25-m DTM (Digital Terrain Model) of Israel, Isr. J.
Earth Sci. 57, no. 3, 145–147.
Hamiel, Y., R. Amit, Z. B. Begin, S. Marco, O. Katz, A. Salamon,
E. Zilberman, and N. Porat (2009). The seismicity along the Dead
Sea fault during the last 60,000 years, Bull. Seismol. Soc. Am. 99,
no. 3, 2020–2026.
Hofstetter, A. (2003). Seismic observations of the 22/11/1995 Gulf of Aqaba
earthquake sequence, Tectonophysics 369, no. 1–2, 21–36, doi
10.1016/S0040-1951(03)00129-X.
Hofstetter, R., Y. Klinger, A.-Q. Amrat, L. Rivera, and L. Dorbath (2007).
Stress tensor and focal mechanisms along the Dead Sea fault and related structural elements based on seismological data, Tectonophysics
429, no. 3–4, 165–181, doi 10.1016/j.tecto.2006.03.010.
Joyner, W. B. (2000). Strong motion from surface waves in deep sedimentary basins, Bull. Seismol. Soc. Am. 90, no. 6B, S95–S112.
Käser, M., M. Dumbser, and J. de la Puente (2006). An efficient ADER-DG
method for 3-dimensional seismic wave propagation in media with
complex geometry, in Proc. from ESG 2006, Third International
Symposium on the Effects of Surface Geology on Seismic Motion,
Grenoble, France.
Kawase, H. (1996). The cause of the Damage Belt in Kobe: “The basin-edge
effect,” constructive interference of the direct S wave with the basininduced diffracted/Rayleigh waves, Seismol. Res. Lett. 67, no. 5,
25–34.
Kristek, J., P. Moczo, and P. Pazak (2006). Numerical modeling of earthquake motion in Grenoble basin, France, using a 4th-order velocitystress arbitrary discontinuous staggered-grid FD scheme, in Proc. from
ESG 2006 Third International Symposium on the Effects of Surface
Geology on Seismic Motion, Grenoble, France.
Larsen, S., R. Wiley, P. Roberts, and L. House (2001). Next-generation
numerical modeling: Incorporating elasticity, anisotropy and attenuation, Soc. Explor. Geophys. Ann. Internat. Mtg., Expanded Abstracts,
1218–1221.
Le Beon, M., Y. Klinger, A. Q. Amrat, A. Agnon, L. Dorbath, G. Baer, J.-C.
Ruegg, O. Charade, and O. Mayyas (2008). Slip rate and locking depth
from GPS profiles across the southern Dead Sea Transform, J. Geophys. Res. 113, no. B11, doi 10.1029/2007JB005280.
Levi, T., R. Weinberger, Y. Eyal, V. Lyakhovsky, and E. Heifetz (2008).
Velocities and driving pressures of clay-rich sediments injected into
clastic dykes during earthquakes, Geophys. J. Int. 175, no. 3,
1095–1107, doi 10.1111/j.1365-246X.2008.03929.x.
Marco, S., and A. Agnon (1995). Prehistoric earthquake deformations near
Masada, Dead Sea graben, Geology 23, no. 8, 695–698.
Marco, S., and A. Agnon (2005). High-resolution stratigraphy reveals
repeated earthquake faulting in the Masada fault zone, Dead Sea
Transform, Tectonophysics 408, no. 1–4, 101–112.
Marco, S., T. Rockwell, A. Heimann, U. Frieslander, and A. Agnon (2005).
Late Holocene activity of the Dead Sea Transform revealed in 3D
palaeoseismic trenches on the Jordan Gorge segment, Earth Planet.
Sci. Lett. 234, no. 1–2, 189–205, doi 10.1016/j.epsl.2005.01.017.
Marco, S., M. Stein, A. Agnon, and H. Ron (1996). Long-term earthquake
clustering: A 50,000-year paleoseismic record in the Dead Sea Graben,
J. Geophys. Res. 101, no. B3, 6179–6191.
Pitarka, A., K. Irikura, T. Iwata, and H. Sekiguchi (1998). Three-dimensional
simulation of the near-fault ground motion for the 1995 Hyogo-Ken
1739
Nanbu (Kobe), Japan, earthquake, Bull. Seismol. Soc. Am. 88, no. 2,
428–440.
Quennell, A. (1956). The structural and geomorphic evolution of the Dead
Sea Rift, Q. J. Geol. Soc. London 114, 1–24.
Sagy, A. (2009). Cross-sections along and across the Dead-Sea basin, Geol.
Surv. Isr., TR-GSI/07/2009.
Scholz, C. H. (2002). The Mechanics of Earthquakes and Faulting Second.
Ed, Cambridge University Press, New York.
Seilacher, A. (1984). Sedimentary structures tentatively attributed to seismic
events, Mar. Geol. 55, no. 1–2, 1–12.
Semblat, J. F., P. Dangla, M. Kham, and A. M. Duval (2002). Seismic site
effects for shallow and deep alluvial basins: In-depth motion and focusing effect, Soil Dynam. Earthquake Eng. 22, no. 9–12, 849–854.
Shapira, A., R. Avni, and A. Nur (1993). A new estimate for the epicenter of the
Jericho earthquake of 11 July 1927, Isr. J. Earth Sci. 42, no. 2, 93–96.
Shapira, A., R. Hofstetter, A. Q. F. Abdallah, J. Dabbeek, and W. Hays
(2007). Earthquake hazard assessments for building codes, U.S.
Agency for International Development, Bureau for Economic Growth,
Agriculture and Trade, Washington, D.C.
Singh, S. K., E. Mena, and R. Castro (1988). Some aspects of source
characteristics of the 19 September 1985 Michoacan earthquake
and ground motion amplification in and near Mexico City from strong
motion data, Bull. Seismol. Soc. Am. 78, no. 2, 451–477.
Smit, J., J. P. Brun, X. Fort, S. Cloetingh, and Z. Ben-Avraham (2008). Salt
tectonics in pull-apart basins with application to the Dead Sea basin,
Tectonophysics 449, 1–16, doi 10.1016/j.tecto.2007.12.004.
Stupazzini, M., R. Paolucci, and H. Igel (2009). Near-fault earthquake
ground-motion simulation in the Grenoble Valley by a highperformance spectral element code, Bull. Seismol. Soc. Am. 99,
no. 1, 286–301, doi 10.1785/0120080274.
ten Brink, U. S., Z. Ben-Avraham, R. E. Bell, M. Hassouneh, D. F. Coleman,
G. Andreasen, G. Tibor, and B. Coakley (1993). Structure of the Dead
Sea Pull-Apart Basin from gravity analyses, J. Geophys. Res. 98,
21,877–21,894.
Wdowinski, S., Y. Bock, G. Baer, L. Prawirodirdjo, N. Bechor, S. Naaman,
R. Knafo, Y. Forrai, and Y. Melzer (2004). GPS measurements of
current crustal movements along the Dead Sea fault, J. Geophys.
Res. 109, B05403. doi 10.1029/2003JB002640.
Department of Geological and Environmental Sciences
Ben Gurion University of the Negev
Beer-Sheva, Israel
(S.S.-K.)
Department of Structural Engineering
Ben Gurion University of the Negev
Beer-Sheva, Israel
(M.T.)
Nevada Seismological Laboratory
University of Nevada
Reno, Nevada
(J.N.L.)
Geological Survey of Israel
Jerusalem, Israel
(Z.G.)
Manuscript received 8 September 2011