Recent studies on the evolution of the Dead Sea basin have shed light on the intricate tectonic regime of the area. Combined with newly available data from Jordan, a new picture of a symmetrical deep basin is emerging. Salt is prevalent over the entire width of the basin in the south. The original thickness of this layer was calculated to be ∼2 km, but at present it does not exceed 900 m. Crustal studies indicate a difference between the southern and northern basins, which are separated by a large, normal fault. Depth to the basement in the northern basin is estimated to be 6–8 km, while that of the southern basin is 12 km. Relocation of deep earthquakes revealed that the majority of well-constrained micro-earthquakes (M L ≤ 3.2) occurred at depths much deeper than previously expected (20–32 km). Seismicity and the low value of regional heat flow suggest that the lower crust might be cool and brittle. A lithospheric strength profile was calculated, indicating a narrow brittle-to-ductile transition at a depth of 31 km. Uplift measurements, submersible studies, and combined geological-geophysical mapping are some of the new techniques applied to the area to solve the complex neotectonic structure. Results indicate that the southern and northern basins are both currently active. In addition to tectonics, activity is also inferred by the presence of salt diapirs, whose uplift or subsidence may be related to current motion along active faults. Discrepancies in earthquake-reoccurrence times may indicate that the main fault in the northern Dead Sea basin, the Jericho fault (also known as the Jordan fault), is segmented, or that earthquakes occur in clusters. One such segment is responsible for the formation of a small subbasin on the northwestern shore of the lake, the Qumran basin, whose complex neotectonic regime includes strike-slip, reverse and normal faulting, folding, right bending splays, and a migrating depocenter. Recent global positioning system measurements provide slip-rates of 2.6–3.8 mm/yr for the current plate motion in this area. An open crack between the seafloor and a sharp bathymetric cliff in the lake provides visual evidence for this motion, while data from shallow seismic surveys present paleoseismic information on this activity.

Abstract The basins in the Eastern Mediterranean can be divided into those that were formed mainly in post-Miocene time and those that were formed during the rifting episodes that led to the formation of the Neotethys. The younger basins can be further divided into those that were formed mainly in post-Miocene time and those that were formed in post-Pliocene time. The separation is not only one of convenience but also corresponds to major adjustments in the plate tectonic situation in the Eastern Mediterranean. The late Miocene deposition of thick evaporites throughout the Mediterranean region, or, where evaporites are missing, the creation of an important erosional unconformity during the extreme lowstand of the Mediterranean, makes the Miocene-Pliocene boundary relatively easy to identify, especially on seismic reflection records. At about the same time, following the collision of the Arabian plate with Eurasia, the Anatolian and Aegean microplates came into existence between the convergent African and Eurasian plates to accommodate tectonic escape between them. The general configuration of the Eastern Mediterranean basins reflects the tectonic and structural gradients between the collisional domain of southeastern Turkey and Iran, and the continuing but increasingly limited subduction along the Calabrian and Hellenic arcs, with the Cyprus and Levantine zones between them. Several distinct zones can be identified in the Eastern Mediterranean. The Dead Sea Fault system marks the edge between the collisional and pre-collisional zones to the east and west, respectively. The meridian through the Anaximander Mountains (30°E) forms a rough boundary between the zone of incipient collision to the east and the zone of continuing but late-stage subduction to the west. The Malta Escarpment forms the Eastern boundary of the Eastern Mediterranean basins. The series of basins along the northern margin of the Eastern Mediterranean and the Aegean Sea share this progressive evolution, with those containing Messinian evaporites to the east and those without to the west. The Sicily Channel with its associated basins is an extensional zone between the Eastern and Western Mediterranean. The basins discussed in this paper are divided into two groups, the larger and older basins and the smaller and younger basins. In the first group are the Ionian Basin and the Levantine Basin, and in the second group the Cilicia Basin, Antalya Basin, Finike Basin, Rhodes Basin, Aegean basins, Sicily Channel basins, Latakia Basin and Larnaca Basin. The Eastern Mediterranean represents the last stage in the evolution of an ocean basin. Given the current motion between Africa and Eurasia, the Eastern Mediterranean will cease to exist in about 6–8 Ma from now. As a result, the larger and older basins are shrinking, whereas the younger and smaller basins are growing. Eventually the smaller basins will also disappear.

The gaps of volcanic activity and the associated shallow-dipping seismicity in South America can be explained by the consumption of the thick-rooted, buoyant, aseismic Nazca and Juan Fernandez Ridges and perhaps also the Cocos Ridge. The ridges erase the trench where they collide with the overriding continent. The point of collision migrates north or south along the plate boundary, depending on the orientation of the ridge relative to the direction of plate motion. This migration leaves behind a zone in which subduction is temporarily stopped; lack of subduction leads to the cessation of volcanism, perhaps owing to lack of water needed for partial melting. Although the present aseismic ridges probably consist of basaltic cumulates, there is some indication that earlier-consumed parts of these ridges (or different, previously consumed ridges) contained continental fragments that are now embedded in the western coast of South America.