Permafrost warming has the potential to amplify global climate change, because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C. Over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere. In the discontinuous zone, however, ground warming occurred due to increased snow thickness while air temperature remained statistically unchanged.

The Northern Patagonian Andes have been constructed through multiple mechanisms that range from tectonic inversion of extensional structures of Early to Middle Jurassic age in the Main Andes to Oligocene in the Precordilleran region. These have acted during two distinctive orogenic stages, first in late Early Cretaceous and later in Miocene times Late Oligocene extension separates these two contractional periods and is recorded by half‐grabens developed in the retroarc region. The last contractional stage coexists with an eastward foreland expansion of the late Miocene arc whose roots are presently exposed as minor granitic stocks and volcanic piles subordinately in the Main Andes, east of the present arc. As a consequence of this orogenic stage a foreland basin has developed, having progressed from 18 Ma in the main North Patagonian Andes, where the mountain front was flooded by a marine transgression corresponding to the base of the Ñirihuau Formation, to 11 Ma in the foreland area. Cannibalization of this foreland basin occurred initially in the hinterland and then progressed to the foreland zone. Blind structures formed a broken foreland at the frontal zone inferred from growth strata geometries. During Pliocene to Quaternary times most of the contractional deformation was dissipated in the orogenic wedge at the time when the arc front retracted to its present position.

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The southern Andes were created by two main cycles of shallow to flat subduction settings that were followed by steepening subduction zones starting in Late Cretaceous times. The first wave of contractional deformation and Andean uplift migrated through the continental interior as a result of two shallow subduction zones, one developed between 36 and 39°S and the other between 40 and 46°S, associated with the expansion of arc magmatism. In latest Cretaceous to Eocene times, its northernmost segment flattened, increasing the compression and uplift of mountains in the far foreland area, whereas, to the south, a steepening subduction zone provoked extensional collapse of vast sectors of the fold and thrust belt followed by within-plate magmatism. The whole area between 36 and 44°S retreated as a large steepening zone in late Oligocene times, inducing asthenosphere injection and the formation of large within-plate plateaux in the foreland zone, as well as narrow extensional basins induced by the incipient collapse of the fold and thrust belt hinterland zone. The late Miocene was characterized by the development of three shallow subduction zones that expanded differentially between 34°30′ and 50°S. These were again associated with arc expansions and lateral construction of the fold and thrust belt. Their evolution finished in Pliocene to Quaternary times with the eruption of within-plate plateaux and widespread extensional deformation that still governs important sectors of the present retroarc area. Finally, an incipient shallow subduction setting could have been developing between 35 and 39°S in the last 3 Ma associated with renewed Andean uplift at these latitudes. Cyclic shallow subduction in the southern Andes, and therefore repeated behaviour of constructional stages followed by collapsing ones associated with voluminous volcanism, could be the consequence of the cycle imposed by the docking of seismic ridges, one achieved in latest Cretaceous (?) to Eocene times and the other in late Miocene times. Other factors, such as the collision of highly serpentinized and therefore isostatically buoyant plateaux, associated with fracture oceanic zones, are also considered to trigger shallow subduction settings.Los Andes del Sur fueron creados a través de dos ciclos principales en los cuales la zona de subducción se subhorizontalizó y posteriormente se empinó en diferentes segmentos comenzando en el Cretácico superior. La primer fase contraccional en los Andes del Sur migró desde el borde de placas hacia el interior continental en relación al desarrollo de dos zonas de subducción subhorizontal, una desarrollada entre los 36°y los 39°S y la otra entre los 40°y los 46°S, ambas relacionadas a la expansión oriental del magmatismo del arco volcánico. En el Cretácico más alto hasta el Eoceno, la sección subhorizontal más septentrional siguió acentuándose asociándose así al levantamiento de relieves montañosos lejanos al límite de placas, al tiempo que el sector meridional se empinó rápidamente lo que provocó el colapso extensio...

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International audienc

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