scholarly journals Modeled temperatures and fluid source distributions for the Mexican subduction zone: Effects of hydrothermal circulation and implications for plate boundary seismic processes

2016 ◽  
Vol 17 (2) ◽  
pp. 550-570 ◽  
Author(s):  
Matthew Perry ◽  
Glenn A. Spinelli ◽  
Ikuko Wada ◽  
Jiangheng He
Keyword(s):  
Subduction Zone ◽  
Plate Boundary ◽  
Hydrothermal Circulation ◽  
Fluid Source ◽  
Mexican Subduction Zone

Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic

1987 ◽  
Vol 321 (1557) ◽  
pp. 163-181 ◽  
Keyword(s):  
New Zealand ◽  
Subduction Zone ◽  
East Coast ◽  
Late Quaternary ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Metamorphic Belt ◽  
Volcanic Region ◽  
The North ◽  
Plate Boundary Zone

The subduction zone under the east coast of the North Island of New Zealand comprises, from east to west, a frontal wedge, a fore-arc basin, uplifted basement forming the arc and the Central Volcanic Region. Reconstructions of the plate boundary zone for the Cainozoic from seafloor spreading data require the fore-arc basin to have rotated through 60° in the last 20 Ma which is confirmed by palaeomagnetic declination studies. Estimates of shear strain from geodetic data show that the fore-arc basin is rotating today and that it is under extension in the direction normal to the trend of the plate boundary zone. The extension is apparently achieved by normal faulting. Estimates of the amount of sediments accreted to the subduction zone exceed the volume of the frontal wedge: underplating by the excess sediments is suggested to be the cause of late Quaternary uplift of the fore-arc basin. Low-temperature—high-pressure metamorphism may therefore be occurring at depth on the east coast and high-temperature—low-pressure metamorphism is probable in the Central Volcanic Region. The North Island of New Zealand is therefore a likely setting for a paired metamorphic belt in the making.

How does the Alpine belt end between Spain and Morocco ?

2002 ◽  
Vol 173 (1) ◽  
pp. 3-15 ◽  
Author(s):  
André Michard ◽  
Ahmed Chalouan ◽  
Hugues Feinberg ◽  
Bruno Goffé ◽  
Raymond Montigny
Keyword(s):  
Subduction Zone ◽  
Plate Boundary ◽  
Western Alps ◽  
Late Eocene ◽  
African Plate ◽  
Northern Margin ◽  
Thrust Tectonics ◽  
Rif Belt ◽  
Transitional Crust ◽  
Roll Back

Abstract The Betic-Rif arcuate mountain belt (southern Spain, northern Morocco) has been interpreted as a symmetrical collisional orogen, partly collapsed through convective removal of its lithospheric mantle root, or else as resulting of the African plate subduction beneath Iberia, with further extension due either to slab break-off or to slab retreat. In both cases, the Betic-Rif orogen would show little continuity with the western Alps. However, it can be recognized in this belt a composite orocline which includes a deformed, exotic terrane, i.e. the Alboran Terrane, thrust through oceanic/transitional crust-floored units onto two distinct plates, i.e. the Iberian and African plates. During the Jurassic-Early Cretaceous, the yet undeformed Alboran Terrane was part of a larger, Alkapeca microcontinent bounded by two arms of the Tethyan-African oceanic domain, alike the Sesia-Margna Austroalpine block further to the northeast. Blueschist- and eclogite-facies metamorphism affected the Alkapeka northern margin and adjacent oceanic crust during the Late Cretaceous-Eocene interval. This testifies the occurrence of a SE-dipping subduction zone which is regarded as the SW projection of the western Alps subduction zone. During the late Eocene-Oligocene, the Alkapeca-Iberia collision triggered back-thrust tectonics, then NW-dipping subduction of the African margin beneath the Alboran Terrane. This Maghrebian-Apenninic subduction resulted in the Mediterranean basin opening, and drifting of the deformed Alkapeca fragments through slab roll back process and back-arc extension, as reported in several publications. In the Gibraltar area, the western tip of the Apenninic-Maghrebian subduction merges with that of the Alpine-Betic subduction zone, and their Neogene roll back resulted in the Alboran Terrane collage astride the Azores-Gibraltar transpressive plate boundary. Therefore, the Betic-Rif belt appears as an asymmetrical, subduction/collision orogen formed through a protracted evolution straightfully related to the Alpine-Apenninic mountain building.

Spatiotemporal Variations in Slow Earthquakes Along the Mexican Subduction Zone

2018 ◽  
Vol 123 (2) ◽  
pp. 1559-1575 ◽  
Author(s):  
J. Maury ◽  
S. Ide ◽  
V. M. Cruz-Atienza ◽  
V. Kostoglodov
Keyword(s):  
Subduction Zone ◽  
Spatiotemporal Variations ◽  
Slow Earthquakes ◽  
Mexican Subduction Zone

The influence of fluids in the unusually high-rate seismicity in the Ometepec segment of the Mexican subduction zone

2021 ◽  
Author(s):  
D Legrand ◽  
A Iglesias ◽  
S K Singh ◽  
V Cruz-Atienza ◽  
C Yoon ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Temporal Distribution ◽  
Aftershock Sequence ◽  
High Rate ◽  
Earth Tides ◽  
P Value ◽  
Plate Interface ◽  
Flow Measurements ◽  
Slow Slip Events ◽  
Mexican Subduction Zone

Summary The rate of earthquakes with magnitudes Mw ≤ 7.5 in the Ometepec segment of the Mexican subduction zone is relatively high as compared to the neighboring regions of Oaxaca and Guerrero. Although the reason is not well understood, it has been reported that these earthquakes give rise to a large number of aftershocks. Our study of the aftershock sequence of the 2012 Mw7.4 Ometepec thrust earthquake suggests that it is most likely due to two dominant factors: (1) The presence of an anomalously high quantity of over-pressured fluids near the plate interface, and (2) the roughness of the plate interface. More than 5,400 aftershocks were manually detected during the first ten days following the 2012 earthquake. Locations were obtained for 2,419 events (with duration magnitudes Md ≥ 1.5). This is clearly an unusually high number of aftershocks for an earthquake of this magnitude. Furthermore, we generated a more complete catalog, using an unsupervised fingerprint technique, to detect more smaller events (15,593 within one month following the mainshock). For this catalog, a high b-value of 1.50 ± 0.10 suggests the presence of fluid release during the aftershock sequence. A low p-value (0.37 ± 0.12) of the Omori law reveals a slow decaying aftershock sequence. The temporal-distribution of aftershocks shows peaks of activity with two dominant periods of 12h and 24h that correlate with the Earth tides. To explain these observations, we suggest that the 2012 aftershock sequence is associated with the presence of over-pressured fluids and/or a heterogeneous and irregular plate interface related to the subduction of the neighboring seamounts. High fluid content has independently been inferred by magneto-telluric surveys and deduced from heat flow measurements in the region. The presence of fluids in the region has also been proposed to explain the occurrence of slow slip events, low frequency earthquakes, and tectonic tremors.

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