Coupled surface to deep Earth processes: Perspectives from TOPO-EUROPE with an emphasis on climate- and energy-related societal challenges

Fast uplift in the southern Patagonian Andes due to long- and short-term deglaciation and the asthenospheric window underneath

“…The initial geotherm is piecewise linear, resulting from an adiabatic temperature gradient of 0.5 °C km −1 in the asthenosphere (Turcotte and Schubert, 2002) and from thermal boundary conditions equal to 0 °C at the surface and 1327 °C at the bottom of the lithosphere, with a nil horizontal heat flux across the vertical boundaries. The rheologic and thermal structure of the reference model gives a lithospheric elastic thickness, T e (sensu Burov and Diament, 1995), of ∼ 30 km, comparable to previous estimates underneath the SPI based on GIA models (Ivins and James, 1999;Dietrich et al, 2010;Lange et al, 2014), heat flow data (Ávila and Dávila, 2018), waveform inversion (Robertson Maurice et al, 2003), and low-temperature thermochronology data (Thomson et al, 2010;Guillaume et al, 2013;Georgieva et al, 2016Georgieva et al, , 2019Stevens Goddard and Fosdick, 2019;Ávila et al, 2023;Muller et al, 2023). Rocks' rheological properties are listed in Table 1.…”

“…However, given the short time intervals investigated here, it seems reasonable to assume that the eroded material is still in the transport zone and therefore does not significantly contribute to unloading the surface of the orogen. If one refers to erosion rates from lowtemperature thermochronology, even though these measures quantify erosion rates over millions of years and not millennia, Fosdick et al (2013), Herman and Brandon (2015), Fernandez et al (2016), andMuller et al (2023) suggest using values between 0.1 and 1 mm yr −1 from 7 to 4 Ma, followed by a period of erosional quiescence (< 0.1 mm yr −1 ) and a possible increase to 1 mm yr −1 in the last ∼ 2 Myr in the SPI region (Muller et al, 2023). Supposing that these erosion rates still apply in the last ∼ 20 000 years, this would translate into 2-20 m of rocks eroded on average since the LGM, leading to local unloading of approximately 60-600 kPa if one assumes a crustal density of 3000 kg m −3 .…”

“…Vertical displacements of the Earth's surface with respect to the geoid occur in response to the motion of crustal and mantle rock masses due to mantle dynamics, plate tectonics, and the redistribution of sediments, water, and ice by surface processes (e.g. Molnar and England, 1990;Watts, 2001;Champagnac et al, 2012;Sternai, 2023;Cloetingh et al, 2023). For instance, an excess of topography in orogenic regions due to convergence, crustal shortening, and magmatism deflects the lithosphere downward, whereas surface unloading by erosion and ice melting causes upward deflection of the lithosphere, known as "isostatic" adjustment (e.g.…”

“…The Chile triple junction (CTJ) at ∼ 46°S delimits the surface tip of the asthenospheric window, which opened during the last ∼ 16 Myr from south to north (Ramos and Kay, 1992;Breitsprecher and Thorkelson, 2009). First-order effects of the asthenospheric flow on the surface continental geology are the inhibition of arc volcanism in favour of retroarc magmatism, reduction in shortening to null or very minor, and rock uplift and exhumation (Ramos and Kay, 1992;Ramos, 2005;Lagabrielle et al, 2004Breitsprecher and Thorkelson, 2009;Guillaume et al, 2009Guillaume et al, , 2013Scalabrino et al, 2010;Lange et al, 2014;Georgieva et al, 2016Georgieva et al, , 2019Ávila and Dávila, 2020;Mark et al, 2022;Ávila et al, 2023;Muller et al, 2023). Rock uplift due to asthenospheric upwelling occurs through dynamic and thermal effects (Guillaume et al, 2009(Guillaume et al, , 2013Conrad and Husson, 2009;Flament et al, 2013;Sternai et al, 2016b;Dávila et al, 2018;Ávila and Dávila, 2020;Faccenna and Becker, 2020;Mark et al, 2022).…”

Fast uplift in the Southern Patagonian Andes due to long and short term deglaciation and the asthenospheric window underneath

“…Vertical displacements of the Earth's surface with respect to the geoid occur in response to the motion of crustal and mantle rock masses due to plate tectonics and the associated redistribution of sediments, water, and ice by surface processes (e.g., Molnar and England, 1990;Watts, 2001;Champagnac et al, 2012;Sternai, 2023;Cloetingh et al, 2023).…”