Figure 1: Map of the Middle East showing locations of crustal profiles. Both refraction and gravity profiles are shown as thick lines. This figure is available in postscript and gif format.
Figure 2(a): Map of the Middle East And North Africa showing earthquake locations extracted from the USGS/NEIC data base. The difference in the magnitudes is represented by the size of the circles. Seismicity shown covers the period of 1960-1990. A more comprehensive earthquake catalog will be developed in the future as part of our database. This figure is available in postscript and gif format.
Figure 2(b): Map of the Middle East and North Africa showing focal mechanism solutions for the period 1977-1992 as reported by Harvard. A more complete catalog for different size earthquakes will be developed as part of our database. This figure is available in postscript and gif format.
Figure 3: Map of the Middle East and North Africa showing only explosion locations (black triangles), extracted from the USGS database (1960-1990). We plan to considerably expand and update this important database. This figure is available in postscript and gif format.
Figure 4: Contour map of Moho depth in Egypt derived from gravity and refraction data after Makris and others (1987). Medium and thick solid lines are contours on Moho. Contour depths are labeled in km. Thick gray lines mark locations of refraction profiles used to constrain Moho. This figure is available in postscript and gif format.
Figure 5: Location map of gravity interpretation profiles in Iran from Snyder and Barazangi (1986). The three profiles are thick gray lines. The Main Zagros Thrust (MZT) is the suture zone between the Arabian plate and the Eurasian plate and is shown as a thick black line, and the Zagros deformation front is shown as a thick black dashed line. Numbers 1-3 show profile numbers of Figure 6. This figure is available in postscript and gif format.
Figure 6: Three crustal density profiles interpreted from gravity data by Snyder and Barazangi (1986). Densities are shown in g-cm-3 with the crustal interfaces (thick solid lines). The profiles have been vertically exaggerated by a factor of two for better readability. See Figure 5 for location of these profiles. This figure is available in postscript and gif format.
Figure 7: Location map for Israel, occupied areas, and nearby countries. Refraction profiles are shown by thick black lines, with Roman numbering, from Ginzburg and Folkman (1980) and Ginzburg and others (1981). Shot point locations are marked with stars and numbered with Arabic numerals. The approximate location of the Dead Sea Fault is shown with a thick gray line and transform motion marked with arrows. The two basins of the Dead Sea and the Sea of Galilee are filled light gray. This figure is available in postscript and gif format.
Figure 8: Two-dimensional velocity structure interpretations of two Israeli refraction lines IIIa and IV running through northern and central Israel, respectively, from the Dead Sea to the Mediterranean, after Ginzburg and Folkman (1980) (see Figure 7 for locations). Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Profiles are shown without vertical exaggeration. This figure is available in postscript and gif format.
Figure 9: Two-dimensional velocity structure interpretation of Israeli refraction line VI running through southern Israel and northern Sinai, after Ginzburg and others (1981). Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Profile is shown without vertical exaggeration at 1:2,000,000 scale. See Figure 7 for location. This figure is available in postscript and gif format.
Figure 10: One-dimensional velocity structure beneath southern Israel and northern Sinai, derived from a Dead Sea shot and arrivals at receivers along line VI (Ginzburg and others, 1981). See Figure 7 for location and Figure 8 for structure of line VI. This figure is available in postscript and gif format.
Figure 11: Composite interpretation of two-dimensional velocity structure along Dead Sea "rift" system after Ginzburg and others (1981). Refraction lines I, II and IIIb were shot along the western margin of the "leaky transform" running along the Gulf of Aqaba through the Dead Sea and Sea of Galilee. Note ~5 km thick transition zone above Moho. Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Deep interface within mantle was observed by wide-angle reflections. Profile is shown with vertical exaggeration, to enhance readability, at 1:4,000,000 horizontal scale. See Figure 7 for location of these profiles. This figure is available in postscript and gif format.
Figure 12: One-dimensional velocity structure along the Jordan-Dead Sea Rift derived from shotpoint 4 and arrivals at receivers along line I and II, see Figure 7 for location of this shot point and the lines (Ginzburg and Makris, 1979) and Figure 11 for structure along these lines. The velocity transition zone above the Moho is shown by curved portion. This figure is available in postscript and gif format.
Figure 13: Bouguer gravity map of Syria, Lebanon and Israel. Contour maps of Bouguer gravity anomalies were digitized and gridded using a 1 km grid cell size. This figure is available in postscript and gif format.
Figure 14: Location map for Jordan. Refraction profiles and interpreted section A-B are shown by thick black and gray lines with Roman numbering for the refraction lines from El-Isa and others (1987). Shot point locations are marked with stars and numbered with Arabic numerals. The approximate location of the Dead Sea Fault is shown with a thick gray line and transform motion marked with arrows. This figure is available in postscript and gif format.
Figure 15: One-dimensional velocity function beneath central Jordan derived from quarry explosion at shot point 3 and recorded along line II (El-Isa and others, 1987). Model 1 (solid line) corresponds to the two-dimensional model of Figure 16 and Model 2 (dashed line) corresponds to a reflectivity synthetic seismogram interpretation of the same data. See Figure 14 for location of line II. This figure is available in postscript and gif format.
Figure 16: Two-dimensional velocity structure interpretation of Jordan refraction line II running through central and southeast Jordan, after El-Isa and others (1987). Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Profile is shown without vertical exaggeration at 1:1,000,000 scale. This figure is available in postscript and gif format.
Figure 17: Two-dimensional velocity structure interpretation of Jordan refraction line I running from central to northwest Jordan, after El-Isa and others (1987). Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Profile is shown without vertical exaggeration at 1:1,000,000 scale. Note that there is a transition zone above the Moho in this interpretation of the line running east of the Dead Sea rift zone. This figure is available in postscript and gif format.
Figure 18: Two-dimensional velocity structure composite section across southern Israel and Jordan, along line A-B of Figure 14, after El-Isa and others (1987). Interpretations of Israeli refraction lines V and II (which are nearly normal to the section) are combined with an interpretation of Jordan lines III and IV in southwestern Jordan. Refraction interfaces are shown by thick lines, with the associated velocities in km/s indicated. Profile is shown without vertical exaggeration at 1:1,000,000 scale. Note that there is a transition zone above the Moho in this interpretation east of the Dead Sea rift zone. This figure is available in postscript and gif format.
Figure 19: Location map for the 1978 profile in Saudi Arabia after Healy and others (1982). Refraction profile receiver locations are shown by thick gray lines. Shot point locations are marked with stars and numbered with large Arabic numerals. The strike-line for the interpreted section is a thick straight line, with small filled squares marking projected Moho points with their depths indicated in km. The boundaries of the exposed Precambrian basement of the Arabian shield are shown as thin solid lines, with the Arabian platform sedimentary rocks to the east and the coastal plain sediments along the Red Sea rift to the west. The extensive Neogene-to-Recent mafic volcanics are filled dark gray. Map projection is Lambert conformal conic with standard parallels at 17¡N and 33¡N. This figure is available in postscript and gif format.
Figure 20: Two-dimensional velocity structure interpretation of the 1978 Saudi Arabian refraction line running from the Red Sea to central Saudi Arabia, after Healy and others (1982) (see Figure 19 for location). Refraction and reflection interfaces and inferred iso-velocity lines are shown by thick lines, with the associated velocities in km/s indicated. Shot point locations are marked with stars at the top of the section. Distance is measured northeast from shot point 6. Note rapid structure change in transition zone from Arabian shield to Red Sea rift beneath shot point 5. Profile is shown with larger vertical exaggeration, to enhance readability, at 1:5,000,000 horizontal scale. This figure is available in postscript and gif format.
Figure 21: Grid of thickness of sedimentary cover in most of the Middle East after Beydoun (1989). The white areas in the grid represent Precambrian basement outcrops. This figure is available in postscript and gif format.
Figure 22: A cross section across the Arabian plate showing surface topography and seismic basement. See Figure 21 for location of this profile. The very thick sedimentary cover in the Mesopotamian foredeep could significantly affect the propagation characteristics of high-frequency crustal seismic phases, such as Pg and Lg. This figure is available in postscript and gif format.
Figure 23: Main menu for access to the database. Land and oceans shades as well as coast lines, country borders and a latitude-longitude grid are the selected choices to be displayed. This figure is available in postscript and gif format.
Figure 24: Map of the Middle East and North Africa obtained by the selection showed in Figure 23. This figure is available in postscript and gif format.
Figure 25: Submenu obtained by clicking on the "display crustal cross sections..." button on the main menu. It allows the user to display a location map with the seismic refraction and gravity lines. By selecting one line with the mouse from the screen, the cross section is displayed next to the location map. This figure is available in postscript and gif format.
Figure 26: An example showing the type of display obtained by using the menu from Figure 25. This figure is available in postscript and gif format.
Figure 27(a): Submenu obtained by clicking on the "seismicity menu...". It allows the user to select by magnitude, depth and time interval. This figure is available in postscript and gif format.
Figure 27(b): Submenu obtained from the "selecting by the type of phenomena..." (see Figure 27(a)). It allows to select by the type of phenomena. In the figure, as an example, all the explosions have been selected from the database. This figure is available in postscript and gif format.
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