scholarly journals Tectonically and climatically driven mountain-hopping erosion in central Guatemala from detrital <sup>10</sup>Be and river profile analysis

2021 ◽  
Vol 9 (4) ◽  
pp. 795-822
Author(s):  
Gilles Brocard ◽  
Jane Kathrin Willenbring ◽  
Tristan Salles ◽  
Michael Cosca ◽  
Axel Guttiérez-Orrego ◽  
...  
Keyword(s):  
Land Surface ◽  
Profile Analysis ◽  
River Sediments ◽  
Water Runoff ◽  
Mountain Range ◽  
Atmospheric Moisture ◽  
River Channels ◽  
Mountain Ranges ◽  
Drainage Patterns ◽  
Cosmogenic 10Be

Abstract. The rise of a mountain range affects moisture circulation in the atmosphere and water runoff across the land surface, modifying the distribution of precipitation and drainage patterns in its vicinity. Water routing in turn affects erosion on hillslopes and incision in river channels on surrounding mountain ranges. In central Guatemala, two parallel, closely spaced mountain ranges formed during two consecutive pulses of uplift, the first between 12 and 7 Ma (Sierra de Chuacús–Sierra de las Minas), and the second after 7 Ma (Altos de Cuchumatanes). We explore the climatic and tectonic processes through which the rise of the most recent range drove the slowing of river incision and hillslope erosion over the previously uplifted range. The 40Ar/39Ar dating of perched volcanic deposits documents the sequential rise and incision of these mountain ranges. Terrestrial cosmogenic 10Be in river sediments indicates that currently hillslopes in the older range erode more slowly than in the younger range (20–150 vs. 300 m Myr−1). These differences mimic the current distribution of precipitation, with the younger range intercepting the atmospheric moisture before it reaches the older range. River channel steepness and deformation of paleovalleys in the new range further indicate that the younger range has been rising faster than the older range up to today. We review how atmospheric moisture interception and river long-profile adjustment to the rise of the new range have contributed to the decline of erosion rates over the old range. We also explore the consequences of this decline and of aridification on the topographic evolution of the older range. The older range undergoes a slow topographic decay, dominated by backwearing, by the stacking of slowly migrating erosion waves along the mountain flanks, and by the formation of pediments around its base. The morphology of the old range is therefore transitioning from that of a front range to that of a dry interior range.

scholarly journals Top-down and bottom-up controls on mountain-hopping erosion: insights from detrital <sup>10</sup>Be and river profile analysis in Central Guatemala

2020 ◽  
Author(s):  
Gilles Y. Brocard ◽  
Jane K. Willenbring ◽  
Tristan Salles ◽  
Michael Cosca ◽  
Axel Guttiérez-Orrego ◽  
...  
Keyword(s):  
Land Surface ◽  
Profile Analysis ◽  
River Sediments ◽  
Mountain Range ◽  
Top Down ◽  
Bottom Up ◽  
Erosion Rates ◽  
River Incision ◽  
Orogenic Plateaus ◽  
Cosmogenic 10Be

Abstract. The presence of a mountain affects the circulation of water in the atmosphere and over the land surface. These effects are felt over some distance, beyond the extent of the mountain, controlling precipitation delivery and river incision over surrounding landmasses. The rise of a new mountain range therefore affects the erosion of pre-existing mountains located in close proximity. We document here this phenomenon in the mountains of Central Guatemala. The 40Ar-39Ar dating of lava flows shows that two parallel, closely spaced mountain ranges formed during two consecutive pulses of single-stepped uplift, one from 12 to 7 Ma, and the second one since 7 Ma. The distribution of erosion rates derived from the analysis of detrital cosmogenic 10Be in river sediments shows that the younger range erodes faster (~300 m/My) than the older one (20–150 m/My), and that erosion correlates with the amount of precipitation. Moisture tracking form the Caribbean Sea is intercepted by the younger range, which casts a rain shadow over the older one. The analysis of river long-profiles provides a record of longer-term interactions between the two ranges. The rivers that drain the older range were diverted by the younger range during the early stages of its rise. A few rivers were able to maintain their course across the young range, through profile steepening, but incision completely stalled along their upper reaches, upstream of the younger range. As a result, the older range has been passively uplifted, and entered a phase of a slow topographic decay: pediments have formed along its base, while ancient upstream-migrating waves of erosion, located farther up the mountain flanks, have almost stopped migrating. Aridification and cessation of river incision together explain the slowing down of erosion over the older range. They represent top-down and bottom-up processes whereby the younger range controls erosion over the older one. These controls are regarded as instrumental in the nucleation and enlargement of orogenic plateaus forming above continental accretionary wedges.

scholarly journals [Re]covering Jeddah’s Wadis – Building the City’s Resilience through Green Infrastructure

2018 ◽  
Vol 11 (4) ◽  
pp. 228
Author(s):  
Hanaa Motasim
Keyword(s):  
Green Infrastructure ◽  
Rain Water ◽  
Mountain Range ◽  
Water Drainage ◽  
Severe Damage ◽  
Mountain Ranges ◽  
Natural Flow ◽  
The Rich ◽  
The City ◽  
Green Corridors

Jeddah, Saudi Arabia’s largest coastal city, is positioned between two prominent natural features: the mountain range on its eastern side and the Red Sea on its west. The city faces many challenges central to which is storm water drainage. The natural drainage of the city through its pre-existing wadis, bringing down the rain water from the steep mountain ranges through the low inclining coastal plane and into the sea, has been interrupted in the last few decades by massive road infrastructural projects cutting through the city and interrupting the natural flow. The outcome of these interventions has been excessive flooding calamities, of which the ones in 2009 and 2011 were the most extreme, causing severe damage to infrastructure, property and lives.In light of climate change the intensity of flash floods is expected to increase, placing enormous stress on the city. To control the floods the city has pushed forward heavily engineered solutions, canalizing the rich network of wadis, almost 80 in number, into 4 major concrete channels that discharge the rain water accumulated in the mountains directly into the sea. This solution, which has been prohibitive in cost, has robbed the city of any potential of utilizing the precious supply of rain water. This paper explores the potential of recovering Jeddah’s wadis and creating green corridors across the city. As opposed to engineered solutions which address singular problematics, green infrastructures could provide numerous benefits to the city and the region as a whole.

scholarly journals Impact of North Atlantic Oscillation on the Snowpack in Iberian Peninsula Mountains

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 105 ◽  
Author(s):  
Esteban Alonso-González ◽  
Juan I. López-Moreno ◽  
Francisco M. Navarro-Serrano ◽  
Jesús Revuelto
Keyword(s):  
North Atlantic Oscillation ◽  
Iberian Peninsula ◽  
Sierra Nevada ◽  
North Atlantic ◽  
Snow Water Equivalent ◽  
Mountain Range ◽  
Winter Climate ◽  
Mountain Ranges ◽  
Iberian Range ◽  
The Impact

The North Atlantic Oscillation (NAO) is considered to be the main atmospheric factor explaining the winter climate and snow evolution over much of the Northern Hemisphere. However, the absence of long-term snow data in mountain regions has prevented full assessment of the impact of the NAO at the regional scales, where data are limited. In this study, we assessed the relationship between the NAO of the winter months (DJFM-NAO) and the snowpack of the Iberian Peninsula. We simulated temperature, precipitation, and snow data for the period 1979–2014 by dynamic downscaling of ERA-Interim reanalysis data, and correlated this with the DJFM-NAO for the five main mountain ranges of the Iberian Peninsula (Cantabrian Range, Central Range, Iberian Range, the Pyrenees, and the Sierra Nevada). The results confirmed that negative DJFM-NAO values generally occur during wet and mild conditions over most of the Iberian Peninsula. Due to the direction of the wet air masses, the NAO has a large influence on snow duration and the annual peak snow water equivalent (peak SWE) in most of the mountain ranges in the study, mostly on the slopes south of the main axis of the ranges. In contrast, the impact of NAO variability is limited on north-facing slopes. Negative (positive) DJFM-NAO values were associated with longer (shorter) duration and higher (lower) peak SWEs in all mountains analyzed in the study. We found marked variability in correlations of the DJFM-NAO with snow indices within each mountain range, even when only the south-facing slopes were considered. The correlations were stronger for higher elevations in the mountain ranges, but geographical longitude also explained the intra-range variability in the majority of the studied mountains.

Field-based measurements of sulfur gas emissions from an agricultural coastal acid sulfate soil, eastern Australia

Soil Research ◽  
2011 ◽  
Vol 49 (6) ◽  
pp. 471 ◽  
Author(s):  
Andrew S. Kinsela ◽  
O. Tom Denmead ◽  
Bennett C. T. Macdonald ◽  
Michael D. Melville ◽  
Jason K. Reynolds ◽  
...  
Keyword(s):  
Land Surface ◽  
Night Time ◽  
Acid Sulfate ◽  
Drainage Patterns ◽  
So2 Flux ◽  
Diurnal Patterns ◽  
Eastern Australia ◽  
Surface Soil Temperature ◽  
Study Sites ◽  
Sulfate Soils

The emissions of biogenic hydrogen sulfide (H2S) and sulfur dioxide (SO2) play important roles in the global atmospheric sulfur (S) cycle. Field-based investigations using ultraviolet fluorescence spectroscopy show that drained acid sulfate soils (ASS) are a potentially unaccounted source of biogenic H2S and SO2. Significant diurnal variations were evident in SO2 fluxes, with average daytime measurements 9.3–16.5-fold greater than night-time emissions. Similar diurnal patterns in H2S fluxes were observed but proved statistically insignificant. The results from simultaneously collected micrometeorological measurements suggest that emissions of SO2 and H2S are most likely occurring via different processes. The SO2 fluxes are closely linked to surface soil temperature and moisture content, whereas H2S is constantly emitted from the land surface at the two study sites. Drained ASS are most likely mapped as agricultural lands rather than drained backswamps. Therefore, these areas are likely to be assigned H2S and SO2 flux values of zero in greenhouse gas species inventories. These findings suggest a need to expand these measurements to other drained ASS areas to refine regional (and possibly global) atmospheric S budgets. Further research is necessary to elucidate the sources of measured S compounds, and specifically whether they are limited to individual agricultural drainage patterns in ASS.

scholarly journals On the shapes of the isogeotherms under mountain ranges in radio-active districts

1910 ◽  
Vol 83 (563) ◽  
pp. 339-346 ◽  
Keyword(s):  
Physical Condition ◽  
Accurate Solution ◽  
Earth’S Crust ◽  
Mountain Range ◽  
Mountain Ranges ◽  
Earth's Crust

The importance attached by geologists to the distribution of temperature within the earth’s crust as a factor in the production of movements of the crust, and in particular in the formation of mountain ranges, has made it necessary to consider if it is possible to determine the distribution of temperature under and in the neighbourhood of a mountain range, by a method more rigid and accurate than that used by Fisher, and more closely following the physical condition of the problem than that used by Thoma. In what follows it will be shown that an accurate solution can be obtained in certain simple cases, even when the soil is radio-active.

On the Synergistic Climatic Effects of Covarying Major Mountain Range Topographies

2020 ◽  
Author(s):  
Sebastian G. Mutz ◽  
Todd A. Ehlers
Keyword(s):  
General Circulation ◽  
Atmospheric Transport ◽  
Circulation Model ◽  
Careful Consideration ◽  
Mountain Range ◽  
Earth Surface ◽  
Climatic Effects ◽  
Climate Conditions ◽  
Mountain Ranges ◽  
The Impact

&lt;p&gt;The interpretation of Earth surface archives often requires consideration of distant off-site events. One such event is the surface uplift of Earth&amp;#8217;s major mountain ranges, which affects climate and the Earth&amp;#8217;s surface globally. In this study, the individual and synergistic climatic effects of topographic changes in major mountain ranges are explored with a series of General Circulation Model (GCM) experiments and analyses of atmospheric teleconnections. The GCM experiments are forced with different topographic scenarios for Himalaya-Tibet (TBT) and the Andes (ADS), while environmental boundary conditions are kept constant. The topographic scenarios are constructed by successively lowering modern topography to 0% of its modern height in increments of 25%. This results in a total of 5 topographic scenarios for TBT (tbt100, tbt075, tbt050, tbt025, tbt000) and ADS (ads100, ads075, ads050, ads025, ads000). TBT scenarios are then nested in ADS scenarios, resulting in a total of 25 experiments with unique topographic settings. The climate for each of those 25 scenarios is simulated with the GCM ECHAM5-wiso. We then explore possible synergies and distant impacts of topographic changes by testing the hypothesis that varying ADS has no effect on simulated climate conditions in the TBT region (c_tbt) and vice versa. This can be expressed as the null hypothesis c_tbt(ads100) = c_tbt(ads075) = c_tbt(ads050) = c_tbt(ads025) = c_tbt(ads000) for each of the 5 TBT scenarios, and vice versa. We conduct Kruskal-Wallis tests for a total of 10 treatment sets to address these hypotheses. The results suggest that ADS climate is mostly independent of TBT topography changes, whereas TBT climate is sensitive to ADS topography changes when TBT topography is high, but insensitive when TBT topography is strongly reduced. Analyses of atmospheric pressure fields suggest that TBT height acts as a control on cross-equatorial atmospheric transport and modifies the impact of ADS topography on northern hemisphere climate. These results dictate a more careful consideration of global (off-site) conditions in the interpretation of Earth surface records.&lt;/p&gt;

Soil-geomorphic significance of land surface characteristics in an arid mountain range, Mojave Desert, USA

CATENA ◽  
2011 ◽  
Vol 87 (3) ◽  
pp. 408-420 ◽  
Author(s):  
Daniel R. Hirmas ◽  
Robert C. Graham ◽  
Katherine J. Kendrick
Keyword(s):  
Land Surface ◽  
Mojave Desert ◽  
Surface Characteristics ◽  
Mountain Range ◽  
Land Surface Characteristics

scholarly journals Maximum Covariance Analysis of Typhoon Surface Wind and Rainfall Relationships in Taiwan

2009 ◽  
Vol 48 (5) ◽  
pp. 997-1016 ◽  
Author(s):  
Hsiao-Chung Tsai ◽  
Tim Hau Lee
Keyword(s):  
Surface Wind ◽  
Correlation Coefficients ◽  
Covariance Analysis ◽  
Mountain Range ◽  
Mountain Ranges ◽  
Maximum Covariance Analysis ◽  
Air Temperatures ◽  
Multivariate Relationships ◽  
River Valleys ◽  
Surface Observations

Abstract The multivariate relationships between hourly surface wind and rainfall observations during typhoons affecting Taiwan have been investigated with maximum covariance analysis (MCA). Historical surface observations from 1987 to 2004 are used when typhoon centers were located inside the domain of 19°–28°N, 117°–127°E. The three leading MCA modes explain 70%, 20.6%, and 7.6% of the squared covariance fraction, and the correlation coefficients are 0.59, 0.48, and 0.49, respectively. The wind directions of the three leading positive modes are 1) northwesterly flow perpendicular to the Snow Mountain Range (SMR), 2) southwesterly flow toward the river valleys of the southwestern Central Mountain Range (CMR) and the southern SMR, and 3) easterly flow toward the northeastern SMR and the northern CMR. The rainfall patterns of the three principal modes reveal the contrast between the windward and the leeward sides of the mountain ranges. Based on the MCA singular vectors, historical typhoon surface wind patterns are categorized into major types. The results show that the three major wind types consist of 53% of the data, with 25%, 9%, and 19%, respectively, for these wind types. Furthermore, the analyses of the corresponding surface air temperatures, relative humidities, and air pressures also reveal contrasting patterns between the windward and leeward sides.

scholarly journals Seasonal habitat use and movements of woodland caribou in the Omineca Mountains, north central British Columbia, 1991-1993

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 365 ◽  
Author(s):  
Mari D. Wood
Keyword(s):  
Habitat Use ◽  
Radio Telemetry ◽  
Mountain Range ◽  
Woodland Caribou ◽  
Heavy Snowfall ◽  
North Central ◽  
Subalpine Fir ◽  
Mountain Ranges ◽  
Engelmann Spruce ◽  
Seasonal Habitat Use

From 1991 to 1993, 30 woodland caribou were captured and fitted with radio-collars west of the Williston Reservoir in north central B.C. Monthly radio-telemetry location flights revealed that caribou in the Northern Area, characterized by a complex of mountain ranges, moved greater distances to calving areas than did those in the South, where only one major mountain range exists. In the year of record heavy snowfall for the area, all collared caribou wintered on windswept alpine slopes, while during the below average snowfall year, many caribou remained in forested habitats. In winter, caribou were found to forage on terrestrial lichens in both lowland lodgepole pine flats and on windswept alpine slopes, and on arboreal lichens in upper elevation Engelmann spruce and subalpine fir forests. There are at least 600-700 caribou in the Omineca Mountains.

scholarly journals Assessing the genetic structure of capercaillie (Tetrao urogallus) in Romania

2020 ◽  
Vol 63 (2) ◽  
pp. 15-26
Author(s):  
Mihai Fedorca ◽  
◽  
Ovidiu Ionescu ◽  
Neculae Șofletea ◽  
Ancuța Fedorca ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Central And Eastern Europe ◽  
Mountain Range ◽  
Tetrao Urogallus ◽  
Mountain Regions ◽  
Genetic Studies ◽  
Mountain Ranges ◽  
Expected Heterozygosity ◽  
European Mountain

Romania holds the most extensive mountain range with oldgrowth forests, in which both habitat surface and capercaillie (Tetrao urogallus) numbers are ones of the highest in Central and Eastern Europe. While previous genetic studies have found that the individuals located in different European mountain ranges are isolated and have highlighted that the species is declining. Here, we are aiming to assess the genetic structure of capercaillie in Romania by genotyping 137 samples collected in the field with 9 STR markers. Expected heterozygosity was 0.586, whereas observed heterozygosity values were 0.859. Population structure analyses indicated weak population differentiation and suggested that sufficient gene flow exists among individuals sampled in different mountain regions. We did not find evidence for a past genetic bottleneck. Our findings contain important information to wildlife managers to focus conservation efforts in areas such as Curvature Carpathians, which serve as a connectivity corridor to avoid eroding the extent or quality of habitat and to prevent further fragmentation.

Sign in / Sign up

Export Citation Format

Share Document