P. Tapponnier - Academia.edu (original) (raw)

Papers by P. Tapponnier

Research paper thumbnail of Propagation of rifting along the Arabia-Somalia plate boundary The Gulfs of Aden and Tadjoura

Journal of Geophysical Research Solid Earth, 1997

The localization and propagation of rifting between Arabia and Somalia are investigated by assess... more The localization and propagation of rifting between Arabia and Somalia are investigated by assessing the deformation geometry and kinematics at different scales between the eastern Gulf of Aden and the Gulf of Tadjoura, using bathymetric, magnetic, seismological, and structural evidence. Large-scale, southwestward propagation of the Aden ridge, markedly oblique to the Arabia-Somalia relative motion vector, began about 30 Myr ago between the Error and Sharbithat ridges. It was an episodic process, with stages of rapid propagation, mostly at rates >10 cm/yr, interrupted by million year pauses on transverse discontinuities coinciding with rheological boundaries between different crustal provinces of the Arabia-Somalia plate. The longest pause was at the Shukra-El Sheik discontinuity (≈45°E), where the ridge tip stalled for ≈13 Myr, between ≈17 and ≈4 Ma. West of that discontinuity, rifting and spreading took place at an azimuth (≈N25°±10°E) and rate (1.2±0.3 cm/yr) different from those of the global Arabia-Somalia motion vector (≈N39°, ≈1.73 cm/yr), implying an additional component of movement (N65°±10°E, 0.7±0.2 cm/yr) due to rotation of the Danakil microplate. At Shukra-El Sheik, the typical oceanic ridge gives way to a narrow, WSW trending axial trough, resembling a large fissure across a shallow shelf. This trough is composed of about eight rift segments, which result from normal faulting and fissuring along N110°-N130°E trends. All the segments step to the left southwestward, mostly through oblique transfer zones with en échelon normal faults. Only two segments show clear, significant overlap. There is one clear transform, the Maskali fault, between the Obock and Tadjoura segments. The latter segment, which encroaches onland, is composed of two parallel subrifts (Iboli, Ambabbo) that propagated northwestward and formed in succession. The most recent, southwestern subrift (Ambabbo) represents the current tip of the Aden ridge. We propose a mechanical model in which the large-scale propagation of the ridge followed a WSW trending zone of maximum tensile stress, while the small-scale propagation of its NW trending segments was dictated by the orientation of that stress. Oblique propagation was a consequence of passive lithospheric necking of the Arabia-Somalia plate along its narrow section, in map view, between Socotra and the kink of the Red Sea-Ethiopian rift, above the Afar plume. Individual ridge segments oriented roughly perpendicular to plate motion, like lithospheric cracks, were forced to jump southward because of confinement within the necking zone. Self-sustaining, plate-scale necking may explain why the Aden ridge did not connect with the Red Sea through Bab El Mandeb but continued straight into Afar.

Research paper thumbnail of Propagation of rifting along the Arabia-Somalia Plate Boundary: The Gulfs of Aden and Tadjoura

Journal of Geophysical Research, 1997

Research paper thumbnail of Coseismic slip on shallow décollement megathrusts: implications for seismic and tsunami hazard

Earth-Science Reviews, 2015

Research paper thumbnail of Coseismic deformation of the 2001 M w = 7.8 Kokoxili earthquake in Tibet, measured by synthetic aperture radar interferometry

Journal of Geophysical Research, 2005

Research paper thumbnail of Evidence for Mesozoic shear along the western Kunlun and Altyn-Tagh fault, northern Tibet (China)

Journal of Geophysical Research, 2003

Research paper thumbnail of Geomorphic evidence for an emergent active thrust along the edge of the Po Plain: The Broni-Stradella fault

Journal of Geophysical Research, 2003

Research paper thumbnail of Fluid flow triggered migration of events in the 1989 Dobi Earthquake sequence of central Afar

Geophysical Research Letters, 1997

Research paper thumbnail of Crustal thickening in Gansu-Qinghai, lithospheric mantle subduction, and oblique, strike-slip controlled growth of the Tibet plateau

Geophysical Journal International, 1998

Research paper thumbnail of Holocene left-slip rate determined by cosmogenic surface dating on the Xidatan segment of the Kunlun fault (Qinghai, China)

Research paper thumbnail of Evidences of Tertiary high temperature dextral shear along the Karakorum fault zone

The 1000 km long NW-SE Karakorum fault zone (KFZ) bounds the Tibetan plateau to the SW. Tertiary ... more The 1000 km long NW-SE Karakorum fault zone (KFZ) bounds the Tibetan plateau to the SW. Tertiary deformation kinematics along this major boundary is a key to understand the crustal and lithospheric deformation of the Tibetan plateau. The dextral displacement rate along the active KFZ is disputed (around 3cm/yr, Liu,1993; 4mm/yr, Brown et al., 2002), and few structures demonstrating pre-Pliocene

Research paper thumbnail of Quaternary Slip on the Southern Segment of the Karakorum Fault and Pulan Graben, Western Tibet

Determining the slip-rate history along the Karakorum Fault is fundamental to understanding its p... more Determining the slip-rate history along the Karakorum Fault is fundamental to understanding its present-day kinematic role in the deformation of Tibet. InSAR data suggest that the Karakorum Fault is barely active (1 ± 3 mm/yr) while field observations and high-resolution satellite images inferred a slip-rate of ~30 mm/yr. Geodetic and Quaternary geologic studies suggest slip-rates between 3.4 ± 5 mm/yr

Research paper thumbnail of Active faulting induced by slip partitioning in Montserrat and link with volcanic activity: New insights from the 2009 GWADASEIS marine cruise data

Geophysical Research Letters, 2010

Research paper thumbnail of Propagation of rifting along the Arabia-Somalia plate boundary The Gulfs of Aden and Tadjoura

Journal of Geophysical Research Solid Earth, 1997

The localization and propagation of rifting between Arabia and Somalia are investigated by assess... more The localization and propagation of rifting between Arabia and Somalia are investigated by assessing the deformation geometry and kinematics at different scales between the eastern Gulf of Aden and the Gulf of Tadjoura, using bathymetric, magnetic, seismological, and structural evidence. Large-scale, southwestward propagation of the Aden ridge, markedly oblique to the Arabia-Somalia relative motion vector, began about 30 Myr ago between the Error and Sharbithat ridges. It was an episodic process, with stages of rapid propagation, mostly at rates >10 cm/yr, interrupted by million year pauses on transverse discontinuities coinciding with rheological boundaries between different crustal provinces of the Arabia-Somalia plate. The longest pause was at the Shukra-El Sheik discontinuity (≈45°E), where the ridge tip stalled for ≈13 Myr, between ≈17 and ≈4 Ma. West of that discontinuity, rifting and spreading took place at an azimuth (≈N25°±10°E) and rate (1.2±0.3 cm/yr) different from those of the global Arabia-Somalia motion vector (≈N39°, ≈1.73 cm/yr), implying an additional component of movement (N65°±10°E, 0.7±0.2 cm/yr) due to rotation of the Danakil microplate. At Shukra-El Sheik, the typical oceanic ridge gives way to a narrow, WSW trending axial trough, resembling a large fissure across a shallow shelf. This trough is composed of about eight rift segments, which result from normal faulting and fissuring along N110°-N130°E trends. All the segments step to the left southwestward, mostly through oblique transfer zones with en échelon normal faults. Only two segments show clear, significant overlap. There is one clear transform, the Maskali fault, between the Obock and Tadjoura segments. The latter segment, which encroaches onland, is composed of two parallel subrifts (Iboli, Ambabbo) that propagated northwestward and formed in succession. The most recent, southwestern subrift (Ambabbo) represents the current tip of the Aden ridge. We propose a mechanical model in which the large-scale propagation of the ridge followed a WSW trending zone of maximum tensile stress, while the small-scale propagation of its NW trending segments was dictated by the orientation of that stress. Oblique propagation was a consequence of passive lithospheric necking of the Arabia-Somalia plate along its narrow section, in map view, between Socotra and the kink of the Red Sea-Ethiopian rift, above the Afar plume. Individual ridge segments oriented roughly perpendicular to plate motion, like lithospheric cracks, were forced to jump southward because of confinement within the necking zone. Self-sustaining, plate-scale necking may explain why the Aden ridge did not connect with the Red Sea through Bab El Mandeb but continued straight into Afar.

Research paper thumbnail of Propagation of rifting along the Arabia-Somalia Plate Boundary: The Gulfs of Aden and Tadjoura

Journal of Geophysical Research, 1997

Research paper thumbnail of Coseismic slip on shallow décollement megathrusts: implications for seismic and tsunami hazard

Earth-Science Reviews, 2015

Research paper thumbnail of Coseismic deformation of the 2001 M w = 7.8 Kokoxili earthquake in Tibet, measured by synthetic aperture radar interferometry

Journal of Geophysical Research, 2005

Research paper thumbnail of Evidence for Mesozoic shear along the western Kunlun and Altyn-Tagh fault, northern Tibet (China)

Journal of Geophysical Research, 2003

Research paper thumbnail of Geomorphic evidence for an emergent active thrust along the edge of the Po Plain: The Broni-Stradella fault

Journal of Geophysical Research, 2003

Research paper thumbnail of Fluid flow triggered migration of events in the 1989 Dobi Earthquake sequence of central Afar

Geophysical Research Letters, 1997

Research paper thumbnail of Crustal thickening in Gansu-Qinghai, lithospheric mantle subduction, and oblique, strike-slip controlled growth of the Tibet plateau

Geophysical Journal International, 1998

Research paper thumbnail of Holocene left-slip rate determined by cosmogenic surface dating on the Xidatan segment of the Kunlun fault (Qinghai, China)

Research paper thumbnail of Evidences of Tertiary high temperature dextral shear along the Karakorum fault zone

The 1000 km long NW-SE Karakorum fault zone (KFZ) bounds the Tibetan plateau to the SW. Tertiary ... more The 1000 km long NW-SE Karakorum fault zone (KFZ) bounds the Tibetan plateau to the SW. Tertiary deformation kinematics along this major boundary is a key to understand the crustal and lithospheric deformation of the Tibetan plateau. The dextral displacement rate along the active KFZ is disputed (around 3cm/yr, Liu,1993; 4mm/yr, Brown et al., 2002), and few structures demonstrating pre-Pliocene

Research paper thumbnail of Quaternary Slip on the Southern Segment of the Karakorum Fault and Pulan Graben, Western Tibet

Determining the slip-rate history along the Karakorum Fault is fundamental to understanding its p... more Determining the slip-rate history along the Karakorum Fault is fundamental to understanding its present-day kinematic role in the deformation of Tibet. InSAR data suggest that the Karakorum Fault is barely active (1 ± 3 mm/yr) while field observations and high-resolution satellite images inferred a slip-rate of ~30 mm/yr. Geodetic and Quaternary geologic studies suggest slip-rates between 3.4 ± 5 mm/yr

Research paper thumbnail of Active faulting induced by slip partitioning in Montserrat and link with volcanic activity: New insights from the 2009 GWADASEIS marine cruise data

Geophysical Research Letters, 2010