Plio-Pleistocene increase of erosion rates in mountain belts in response to climate change

Terra Nova ◽  
2015 ◽  
Vol 28 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Frédéric Herman ◽  
Jean-Daniel Champagnac
Keyword(s):  
Climate Change ◽  
Erosion Rates ◽  
Mountain Belts

scholarly journals Long-term erosion of the Nepal Himalayas by bedrock landsliding: the role of monsoons, earthquakes and giant landslides

2019 ◽  
Vol 7 (1) ◽  
pp. 107-128 ◽  
Author(s):  
Odin Marc ◽  
Robert Behling ◽  
Christoff Andermann ◽  
Jens M. Turowski ◽  
Luc Illien ◽  
...  
Keyword(s):  
Frequency Distribution ◽  
Sampling Time ◽  
Clear Correlation ◽  
Size Frequency Distribution ◽  
Meteorological Forcing ◽  
Erosion Rates ◽  
Size Frequency ◽  
Heavy Tailed ◽  
Mountain Belts

Abstract. In active mountain belts with steep terrain, bedrock landsliding is a major erosional agent. In the Himalayas, landsliding is driven by annual hydro-meteorological forcing due to the summer monsoon and by rarer, exceptional events, such as earthquakes. Independent methods yield erosion rate estimates that appear to increase with sampling time, suggesting that rare, high-magnitude erosion events dominate the erosional budget. Nevertheless, until now, neither the contribution of monsoon and earthquakes to landslide erosion nor the proportion of erosion due to rare, giant landslides have been quantified in the Himalayas. We address these challenges by combining and analysing earthquake- and monsoon-induced landslide inventories across different timescales. With time series of 5 m satellite images over four main valleys in central Nepal, we comprehensively mapped landslides caused by the monsoon from 2010 to 2018. We found no clear correlation between monsoon properties and landsliding and a similar mean landsliding rate for all valleys, except in 2015, where the valleys affected by the earthquake featured ∼5–8 times more landsliding than the pre-earthquake mean rate. The long-term size–frequency distribution of monsoon-induced landsliding (MIL) was derived from these inventories and from an inventory of landslides larger than ∼0.1 km2 that occurred between 1972 and 2014. Using a published landslide inventory for the Gorkha 2015 earthquake, we derive the size–frequency distribution for earthquake-induced landsliding (EQIL). These two distributions are dominated by infrequent, large and giant landslides but under-predict an estimated Holocene frequency of giant landslides (> 1 km3) which we derived from a literature compilation. This discrepancy can be resolved when modelling the effect of a full distribution of earthquakes of variable magnitude and when considering that a shallower earthquake may cause larger landslides. In this case, EQIL and MIL contribute about equally to a total long-term erosion of ∼2±0.75 mm yr−1 in agreement with most thermo-chronological data. Independently of the specific total and relative erosion rates, the heavy-tailed size–frequency distribution from MIL and EQIL and the very large maximal landslide size in the Himalayas indicate that mean landslide erosion rates increase with sampling time, as has been observed for independent erosion estimates. Further, we find that the sampling timescale required to adequately capture the frequency of the largest landslides, which is necessary for deriving long-term mean erosion rates, is often much longer than the averaging time of cosmogenic 10Be methods. This observation presents a strong caveat when interpreting spatial or temporal variability in erosion rates from this method. Thus, in areas where a very large, rare landslide contributes heavily to long-term erosion (as the Himalayas), we recommend 10Be sample in catchments with source areas > 10 000 km2 to reduce the method mean bias to below ∼20 % of the long-term erosion.

Tropical rock coasts

2012 ◽  
Vol 37 (2) ◽  
pp. 206-226 ◽  
Author(s):  
Cherith A. Moses
Keyword(s):  
Climate Change ◽  
Temporal Variations ◽  
Future Research ◽  
Published Data ◽  
Time And Space ◽  
Erosion Rates ◽  
The Tropics ◽  
Over Time ◽  
Impacts Of Climate Change

Rock coasts are widespread in the tropics and exhibit particular morphologies that may be specific to their tropical, micro-tidal location. Notches are particularly well developed, often linked to onshore cliffs and fronted by subhorizontal platforms. Through a review of previously published data across the tropics, average cliff face erosion rates are calculated as 2.15 ± 2.62 mm a−1, intertidal erosion rates 3.03 ± 7.50 mm a−1 and subtidal erosion rates 0.96 ± 0.44 mm a−1. Intertidal erosion rates are variable within and across latitudinal ranges: within 10°N and S of the equator average rates are 1.42 ± 1.22 mm a−1; between latitudes of 10°and 20°, 0.88 ± 1.16 mm a−1 and between latitudes of 20°and 30°, 2.04 ± 2.57 mm a−1. A consideration of temporal variations in intertidal erosion rates provides insights into the potential impacts of climate change on the erosion dynamics of rock coasts in the tropics. This paper highlights some of the interactions over time and space between process and measurement that continue to limit our understanding of, and ability to model, the erosion dynamics of tropical rock coasts. It concludes by identifying potentially fruitful areas for future research.

scholarly journals Long-term erosion of the Nepal Himalayas by bedrock landsliding: the role of monsoons, earthquakes and giant landslides

2018 ◽  
Author(s):  
Odin Marc ◽  
Robert Behling ◽  
Christoff Andermann ◽  
Jens M. Turowski ◽  
Luc Illien ◽  
...  
Keyword(s):  
Frequency Distribution ◽  
Sampling Time ◽  
Clear Correlation ◽  
Size Frequency Distribution ◽  
Meteorological Forcing ◽  
Erosion Rates ◽  
Size Frequency ◽  
Heavy Tailed ◽  
Mountain Belts

Abstract. In active mountain belts with steep terrain bedrock landsliding is a major erosional agent. In the Himalayas, landsliding is driven by annual hydro-meteorological forcing due to the summer monsoon and by rarer, exceptional events, such as earthquakes. Independent methods yield erosion rate estimates that appear to increase with sampling time, suggesting that rare, high magnitude erosion events dominate the erosional budget. Nevertheless, until now, neither the contribution of monsoon and earthquakes to landslide erosion, nor the proportion of erosion due to rare, giant landslides have been quantified in the Himalayas. We address these challenges by combining and analyzing earthquake and monsoon induced landslide inventories across different timescales. With time-series of 5 m satellite images over four main valleys in Central Nepal, we comprehensively mapped landslides caused by the monsoon from 2010 to 2018. We found no clear correlation between monsoon properties and landsliding, and a similar mean landsliding rate for all valleys, except in 2015, where the valleys affected by the earthquake featured ~ 5–8 times more landsliding than the pre-earthquake mean rate. The long-term size-frequency distribution of monsoon induced landslides (MIL) was derived from these inventories and from an inventory of landslides larger than ~ 0.1 km2 that occurred between 1972 and 2014. Using a published landslide inventory for the Gorkha 2015 earthquake, we derive the size-frequency distribution for earthquake-induced landslides (EQIL). These two distributions are dominated by infrequent, large and giant landslides, but underpredict an estimated Holocene frequency of giant landslides (> 1 km3) which we derived from a literature compilation. This discrepancy can be resolved when modelling the effect of a full distribution of earthquake of variable magnitude and considering that shallower earthquake may cause larger landslides. In this case, EQIL and MIL contribute about equally to a total long-term erosion of ~ 2 ± 0.75 mm.yr−1 in agreement with most thermochronological data. Independently of the specific total and relative erosion rates, the heavy-tailed size-frequency distribution from MIL and EQIL and the very large maximal landslide size in the Himalayas indicate that mean landslide erosion rates increase with sampling time, as has been observed for independent erosion estimates. Further, we find that the sampling time scale required for adequately capturing the frequency of the largest landslides, which is necessary for deriving long-term mean erosion rates, is often much longer than the averaging time of cosmogenic 10Be methods. This observation presents a strong caveat when interpreting spatial or temporal variability of erosion rates from this method.

Topographic evolution of mountain belts controlled by rheology and surface process efficiency

2020 ◽  
Author(s):  
Sebastian G. Wolf ◽  
Ritske S. Huismans ◽  
Jean Braun ◽  
Xiaoping Yuan
Keyword(s):  
Steady State ◽  
Process Efficiency ◽  
Surface Process ◽  
Tight Coupling ◽  
Active Growth ◽  
Term Survival ◽  
Erosion Rates ◽  
Mountain Belt ◽  
Tectonically Active ◽  
Mountain Belts

<p>It has been a long-standing problem how mountain belts gain and loose topography during their tectonically active growth and inactive decay phase. It is widely recognized that mountain belt topography is generated by crustal shortening, and lowered by river bedrock erosion, linking climate to tectonics. However, it remains enigmatic how to reconcile high erosion rates in active orogens as observed in Taiwan or New Zealand, with long term survival of topography for 100s of Myrs as observed for example in the Uralides and Appalachians. Here we use for the first time a tight coupling between a landscape evolution model (FastScape) with an upper mantle scale tectonic (thermo-mechanical) model to investigate the different stages of mountain belt growth and decay. Using two end-member models, we demonstrate that growing orogens with high erosive power remain small (<200 km), reach steady state between tectonic in- and erosional material eff-flux, and are characterized by transverse valleys. Contrarily, mountain belts with medium to low erosive power will not reach growth steady state, grow wide, and are characterized by longitudinal rivers deflected by active thrusting. However, during growth both types of orogens reach the same height, controlled by rheology and independent of surface process efficiency. Erosional efficiency controls orogenic decay, which is counteracted by regional isostatic rebound. Rheological control of mountain height implies that there is a natural upper limit for the steepness index of rivers on Earth. To compare model results to various natural examples, we quantify the degree of longitudinal flow of modeled rivers with river “longitudinality” in several active or recently active orogens on Earth. Application of the river “longitudinality index” gives information whether (parts of) an orogen is or was at steady state during orogenic growth.</p>

scholarly journals Small crater modification on Meridiani Planum and implications for erosion rates and climate change on Mars

2014 ◽  
Vol 119 (12) ◽  
pp. 2522-2547 ◽  
Author(s):  
M. P. Golombek ◽  
N. H. Warner ◽  
V. Ganti ◽  
M. P. Lamb ◽  
T. J. Parker ◽  
...  
Keyword(s):  
Climate Change ◽  
Erosion Rates ◽  
Meridiani Planum ◽  
Small Crater

scholarly journals Tectonic controls on Quaternary landscape evolution in the Ventura basin, southern California, USA, quantified using cosmogenic isotopes and topographic analyses

2022 ◽  
Author(s):  
A. Hughes ◽  
D.H. Rood ◽  
D.E. DeVecchio ◽  
A.C. Whittaker ◽  
R.E. Bell ◽  
...  
Keyword(s):  
Southern California ◽  
Response Times ◽  
Tectonic Uplift ◽  
Reverse Fault ◽  
Slip Rates ◽  
Oak Ridge ◽  
Erosion Rates ◽  
Exposure Dating ◽  
Ventura Basin ◽  
Mountain Belts

The quantification of rates for the competing forces of tectonic uplift and erosion has important implications for understanding topographic evolution. Here, we quantify the complex interplay between tectonic uplift, topographic development, and erosion recorded in the hanging walls of several active reverse faults in the Ventura basin, southern California, USA. We use cosmogenic 26Al/10Be isochron burial dating and 10Be surface exposure dating to construct a basin-wide geochronology, which includes burial dating of the Saugus Formation: an important, but poorly dated, regional Quaternary strain marker. Our ages for the top of the exposed Saugus Formation range from 0.36 +0.18/−0.22 Ma to 1.06 +0.23/−0.26 Ma, and our burial ages near the base of shallow marine deposits, which underlie the Saugus Formation, increase eastward from 0.60 +0.05/−0.06 Ma to 3.30 +0.30/−0.41 Ma. Our geochronology is used to calculate rapid long-term reverse fault slip rates of 8.6−12.6 mm yr−1 since ca. 1.0 Ma for the San Cayetano fault and 1.3−3.0 mm yr−1 since ca. 1.0 Ma for the Oak Ridge fault, which are both broadly consistent with contemporary reverse slip rates derived from mechanical models driven by global positioning system (GPS) data. We also calculate terrestrial cosmogenic nuclide (TCN)-derived, catchment-averaged erosion rates that range from 0.05−1.14 mm yr−1 and discuss the applicability of TCN-derived, catchment-averaged erosion rates in rapidly uplifting, landslide-prone landscapes. We compare patterns in erosion rates and tectonic rates to fluvial response times and geomorphic landscape parameters to show that in young, rapidly uplifting mountain belts, catchments may attain a quasi-steady-state on timescales of <105 years even if catchment-averaged erosion rates are still adjusting to tectonic forcing.

Low long-term erosion rates in high-energy mountain belts: Insights from thermo- and biochronology in the Eastern Pyrenees

2009 ◽  
Vol 278 (3-4) ◽  
pp. 208-218 ◽  
Author(s):  
Y. Gunnell ◽  
M. Calvet ◽  
S. Brichau ◽  
A. Carter ◽  
J.-P. Aguilar ◽  
...  
Keyword(s):  
High Energy ◽  
Erosion Rates ◽  
Eastern Pyrenees ◽  
Mountain Belts

scholarly journals Extracting information on the spatial variability in erosion rate stored in detrital cooling age distributions in river sands

2017 ◽  
Author(s):  
Jean Braun ◽  
Lorenzo Gemignani ◽  
Peter van der Beek
Keyword(s):  
Steady State ◽  
Spatial Variability ◽  
Erosion Rate ◽  
Regional Scale ◽  
River System ◽  
Eastern Himalaya ◽  
Relative Distribution ◽  
Simple Method ◽  
Erosion Rates ◽  
Mountain Belts

Abstract. The purpose of detrital thermochronology is to provide constraints on regional scale exhumation rate and its spatial variability in actively eroding mountain ranges. Procedures that use cooling age distributions coupled with hypsometry and thermal models have been developed in order to extract quantitative estimates of erosion rate and its spatial distribution, assuming steady state between tectonic uplift and erosion. This hypothesis precludes the use of these procedures to assess the likely transient response of mountain belts to changes in tectonic or climatic forcing. In this paper, we describe a simple method that, using the observed detrital mineral age distributions collected in a system of river catchments, allows to extract information about the relative distribution of erosion rates in an eroding hinterland without relying on a steady-state assumption or the value of thermal parameters. The model is based on a relatively low number of parameters describing lithological variability among the various catchments and their sizes, and only uses the raw binned ages. In order to illustrate the method, we invert age distributions collected in the Eastern Himalaya, one of the most tectonically active places on Earth. From the inversion of the cooling age distributions we predict present day erosion rates of the catchments along the Siang-Tsangpo-Brahmaputra river system, as well as smaller tributaries. We show that detrital age distributions contain dual information about present-day erosion rate, i.e. from the predicted distribution of surface ages within each catchment and from the relative contribution of any given catchment to the river distribution. The inversion additionally allows comparing modern erosion rates to long-term exhumation rates. We provide a simple implementation of the method in R.code within a Jupyter Notebook that includes the data used in this paper for illustration purposes.

scholarly journals Evaluating the Impacts of Climate Change on Soil Erosion Rates in Central Mexico

2017 ◽  
Vol 3 (3) ◽  
pp. 327-351
Author(s):  
Santos Martínez-Santiago ◽  
◽  
Armando López-Santos ◽  
Guillermo González-Cervantes ◽  
Gerardo Esquivel-Arriaga ◽  
...  
Keyword(s):  
Climate Change ◽  
Soil Erosion ◽  
Central Mexico ◽  
Erosion Rates ◽  
Soil Erosion Rates ◽  
Impacts Of Climate Change
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