DInSAR monitoring of glacier dynamics in Cordillera Blanca and Vilcabamba

Author(s):  
Christian Riveros Lizana ◽  
Raul Espinoza Villar ◽  
Harrison Jara Infantes ◽  
Juan Carlos Torres Lazaro

<p>The effects of climate change are causing atypical changes dynamics of tropical glaciers. Conventional methods and optical images were ineffective in measuring these changes periodically due to the complexity of remote mountainous regions and cloud cover. In this research, a Differential Interferometric Synthetic Aperture Radar (DInSAR) analysis has gone performed with Sentinel-1 data from February 2019 to March 2020 in the Cordillera Blanca and Vilcabamba for Mapping displacement and subsidence. The measurements were compared with surface temperature and precipitation, providing zonal statistics to identify and assess regions associated with Glacial Lake Outburst Floods (GLOFs) hazards and enhanced understanding of the glacier dynamics in response to changing climatic conditions.</p>

Landslides ◽  
2016 ◽  
Vol 13 (6) ◽  
pp. 1461-1477 ◽  
Author(s):  
J. Klimeš ◽  
J. Novotný ◽  
I. Novotná ◽  
B. Jordán de Urries ◽  
V. Vilímek ◽  
...  

2021 ◽  
Author(s):  
Sajid Ali ◽  
Garee Khan ◽  
Wajid Hassan ◽  
Javed Akhter Qureshi ◽  
Iram Bano

Abstract Ice masses and snow of Hunza River Basin (HRB) are an important primary source of fresh water and lifeline for downstream inhabitants. Changing climatic conditions seriously put an impact on these available ice and snow masses. These glaciers may affect downstream population by glacial lake outburst floods (GLOF) and surge events due to climatic variation. So, monitoring of these glaciers and available ice masses are important. This research delivers an approach for selected glaciers of the Hunza river basin. An attempt is made in this study using Landsat (OLI, ETM, ETM+, TM), digital elevation model (DEM), Geographic Information System and Remote Sensing techniques (RS&GIS) techniques. We delineated 27 glaciers within HRB from the period of 1990-2018. These glaciers' total area is about 2589.75 ±86km 2 in 1990 and about 2565.12 ±68km 2 in 2018. Our results revealed that from 2009 to 2015, glacier coverage of HRB advanced with a mean annual advance rate of 2.22±0.1 km 2 a -1 . Conversely, from 1994 to 1999, the strongest reduction in glacier area with a mean rate of - 3.126±0.3km 2 a -1 is recorded. The glaciers of HRB are relatively stable compared to Hindukush, Himalayan and Tibetan Plateau (TP) region of the world. The steep slope glacier's retreat rate is more than that of gentle slope glaciers, and the glaciers below elevation of 5000 m above sea level change significantly. Based on climate data from 1995-2018, HRB shows a decreasing trend in temperature and increasing precipitation. The glacier area's overall retreat is due to an increase in summer temperature while the glacier advancement is induced possibly by winter and autumn precipitation.


2010 ◽  
Vol 56 (199) ◽  
pp. 861-870 ◽  
Author(s):  
Denny M. Capps ◽  
Bernhard Rabus ◽  
John J. Clague ◽  
Daniel H. Shugar

AbstractThe temporary storage and subsequent release of water at glacial margins can cause severe flooding in downstream areas and substantially impact glacier dynamics. Alpine subglacial lakes may not be identified until they become subaerially exposed or release a jokulhlaup. We use interferometric synthetic aperture radar (InSAR) to identify and characterize three dynamic alpine subglacial lakes of Brady Glacier, Alaska, USA. We quantify changes in vertical displacement of the glacier surface and lake volumes from September 1995 through March 1996 using European Remote-sensing Satellite-1/-2 (ERS- 1/-2) tandem data. In the autumn, subsidence ranged from 4 to 26cmd-1 and the volume of water discharged ranged from 22 000 ± 2000 to 243 000 ± 14 000m3d-1. Subsidence and discharge rates declined significantly during the winter and continued at a lesser rate through March. Application of this technique may allow researchers to locate alpine subglacial lakes years or decades before they begin to release hazardous outburst floods and substantially impact glacier dynamics.


2014 ◽  
Vol 11 (2) ◽  
pp. 2391-2439 ◽  
Author(s):  
A. Emmer ◽  
V. Vilímek

Abstract. This paper presents a new and easily repeatable objective method for assessing the potential hazardousness of glacial lakes within the Peruvian region of Cordillera Blanca (excluding ice-dammed lakes, which do not reach significant volumes in this region). The presented method was designed to meet four basic principles, which we considered as being crucial. These are: (a) principle of regional focus; (b) principle of objectivity; (c) principle of repeatability; and (d) principle of multiple results. Potential hazardousness is assessed based on a combination of decision trees for clarity and numerical calculation for objectivity. A total of seventeen assessed characteristics are used, of which seven have yet to be used in this context before. Also, several ratios and calculations are defined for the first time. We assume that it is not relevant to represent the overall potential hazardousness of a particular lake by one result (number), thus the potential hazardousness is described in the presented method by five separate results (representing five different glacial lake outburst flood scenarios). These are potentials for: (a) dam overtopping resulting from a dynamic slope movement into the lake; (b) dam overtopping following the flood wave originating in a lake situated upstream; (c) dam failure resulting from a dynamic slope movement into the lake; (d) dam failure following the flood wave originating in a lake situated upstream; and (e) dam failure following a heavy earthquake. All of these potentials theoretically range from 0 to 1. The presented method was verified on the basis of assessing the pre-flood conditions of seven lakes which have produced ten glacial lake outburst floods in the past and ten lakes which have not. A comparison of these results showed that the presented method successfully identifies the potentially hazardous lakes.


2018 ◽  
Author(s):  
Andres Chimira N. ◽  
Eyles Carolyn H. ◽  
Harrinson Jara, ◽  
Rodrigo Narro-Pérez

El impacto del calentamiento global es especialmente evidente en las regiones de gran altitud de la Cordillera Blanca en Perú, donde los glaciares andinos de valle están retrocediendo rápidamente. Debido al aumento del deshielo y el retroceso de los glaciares, grandes lagos pro-glaciares están formando en frente, retenidos por inestables diques de morrenas frontales y laterales. Estos diques morrénicos, confinados dentro de angostos valles desglaciados, son propensos a fallar y pueden liberar GLOFs (glacial lake outburst floods) catastróficos. Tales aluviones atraviesan rápidamente estos valles angostos, erosionando sedimento preexistente y depositando materiales a medida que disminuyen en energía. Es importante entender la naturaleza y la distribución espacial de los sedimentos que ahora rellenan estos angostos valles desglaciados porque ejercen un control crítico sobre el movimiento de las aguas superficiales y subterráneas, las cuales son recursos importantes para las comunidades del área. Este artículo documenta sedimentos de relleno de valle expuestos en un afloramiento de ocho metros de altura en un costado de la Quebrada Cojup, cerca de la ciudad de Huaraz en la Cordillera Blanca. Este afloramiento expone sedimentos que fueron depositados en un lago represado por una morrena, el paleolago Jircacocha que anteriormente ocupaba la parte media de la quebrada. Dentro del afloramiento, se delinearon siete zonas de facies, dominadas por gravas masivas en capas toscas (Gms), arenas y gravas con estratificación entrecruzada (St/Gt) y limos y arcillas deformadas (Fd). Estas zonas de facies se agruparon en cuatro asociaciones de facies que permitieron la interpretación de los procesos deposicionales y las condiciones paleoambientales que transicionaron de un sistema delta alto/fluvial (FA1), a un sistema lacustre (FA2), a un sistema GLOF-dominado (FA3) y finalmente a un sistema de drenaje lacustre-fluvial (FA4). Esta investigación establece las características de los sedimentos que rellenan la parte media de un valle desglaciado y sirve como base para el desarrollo de modelos sedimentológicos y de landsystems más amplios que pueden usarse para mejorar la comprensión de la historia deposicional y la importancia hidrogeológica de sucesiones sedimentarias de relleno de valle que están formando rápidamente en regiones desglaciadas.


2020 ◽  
Author(s):  
Marius L. Huber ◽  
Maarten Lupker ◽  
Sean F. Gallen ◽  
Marcus Christl ◽  
Ananta P. Gajurel

Abstract. Large boulders, ca. 10 m in diameter or more, commonly linger Himalayan river channels. In many cases, their lithology is only compatible with source areas located > 10 km upstream suggesting long transport distances. The mechanisms and timing of exotic boulder emplacement are poorly constrained, but their presence hints at processes that are significant for landscape evolution and geohazard assessments in mountainous regions. We surveyed river reaches of the Trishuli and Sunkoshi, two trans-Himalayan rivers in central Nepal to improve understanding of the processes responsible for exotic boulder transport and the timing of emplacement. Boulder size and channel hydraulic geometry were used to constrain paleo-discharges and boulder emplacement ages were determined using cosmogenic nuclide exposure dating. Modelled discharges required for boulder transport, of ca. 103 to 105 m3/s, exceed typical monsoonal floods in these river reaches. Exposure ages range between ca. 1.5 and 13.5 kyrs BP with clustering of ages around 4.5–5 kyrs BP in both studied valleys. This later period is coeval with a broader weakening of the Indian summer monsoon and glacial retreat after the Early Holocene Climatic Optimum (EHCO), suggesting Glacial Lake Outburst Floods (GLOFs) as a possible cause for boulder transport. We, therefore, propose that these exceptional events are climate-driven, but counter-intuitively occur in the wake of transitions to drier and warmer climates leading to glacier retreat rather than during wetter periods. Furthermore, the old ages and prolonged preservation of these large boulders in or near the active channels shows that these infrequent events have long-lasting consequences on valley bottoms and channel morphology. Overall this study sheds light on the possible coupling between large-infrequent events and bedrock incision patterns in Himalayan rivers with broader implications on landscape evolution.


Geomorphology ◽  
2020 ◽  
Vol 365 ◽  
pp. 107178 ◽  
Author(s):  
Adam Emmer ◽  
Stephan Harrison ◽  
Martin Mergili ◽  
Simon Allen ◽  
Holger Frey ◽  
...  

2020 ◽  
Vol 8 (3) ◽  
pp. 769-787
Author(s):  
Marius L. Huber ◽  
Maarten Lupker ◽  
Sean F. Gallen ◽  
Marcus Christl ◽  
Ananta P. Gajurel

Abstract. Large boulders, ca. 10 m in diameter or more, commonly linger in Himalayan river channels. In many cases, their lithology is consistent with source areas located more than 10 km upstream, suggesting long transport distances. The mechanisms and timing of “exotic” boulder emplacement are poorly constrained, but their presence hints at processes that are relevant for landscape evolution and geohazard assessments in mountainous regions. We surveyed river reaches of the Trishuli and Sunkoshi, two trans-Himalayan rivers in central Nepal, to improve our understanding of the processes responsible for exotic boulder transport and the timing of emplacement. Boulder size and channel hydraulic geometry were used to constrain paleo-flood discharge assuming turbulent, Newtonian fluid flow conditions, and boulder exposure ages were determined using cosmogenic nuclide exposure dating. Modeled discharges required for boulder transport of ca. 103 to 105 m3 s−1 exceed typical monsoonal floods in these river reaches. Exposure ages range between ca. 1.5 and 13.5 ka with a clustering of ages around 4.5 and 5.5 ka in both studied valleys. This later period is coeval with a broader weakening of the Indian summer monsoon and glacial retreat after the Early Holocene Climatic Optimum (EHCO), suggesting glacial lake outburst floods (GLOFs) as a possible cause for boulder transport. We, therefore, propose that exceptional outburst events in the central Himalayan range could be modulated by climate and occur in the wake of transitions to drier climates leading to glacier retreat rather than during wetter periods. Furthermore, the old ages and prolonged preservation of these large boulders in or near the active channels shows that these infrequent events have long-lasting consequences on valley bottoms and channel morphology. Overall, this study sheds light on the possible coupling between large and infrequent events and bedrock incision patterns in Himalayan rivers with broader implications for landscape evolution.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Norbert Szymański ◽  
Sławomir Wilczyński

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.


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