Crustal Structure of Israel: Constraints From Teleseismic and Gravity Data

SUMMARY The structure of the crust in Israel was studied using P ‐wave traveltime residuals of 169 teleseisms recorded by a seismic network throughout the country. Independently of the teleseismic residuals, the Bouguer gravity anomalies were used as an additional aid to examine the structure of the crust. the average time difference between the traveltime residuals in the north and in the south of Israel, is up to 0.2s. Three distinct provinces are observed in the teleseismic residuals, with distinct boundareis at 31.5°N and 30.25°N. Similar differences of traveltime residuals were derived for each of the four principal azimuth quadrants. Most of the difference in traveltime residuals between northern and southern Israel can be explained by changes in the sedimentary thickness. We suggest that the structure of the northern province is significantly different from the central or the southern provinces. If the Moho shallows by about 13–15 km along the profile, as was previously suggested by seismic refraction data, a thickening of the sedimentary sequence to about 15 km in the northern province is needed to satisfy the traveltime residuals. Similar results are obtained if the Bouguer gravity anomalies due to the thickening sediments and the rise of the Moho depth are modelled. In the Eilat region, the sedimentary sequence thins in the SSE direction from the Negev to the Gulf of Eilat, implying a decrease of the Moho in the southward direction by about 10 km, in agreement with the crustal refraction studies.