Recent Changes Occurred in the Terminus of the Debriscovered Bilafond Glacier in the Karakoram Himalayas Using Remotely Sensed Images and Digital Elevation Models(1978-2011)

Recent changes occurred in terminus of the debris-covered Bilafond Glacier in the Karakoram Range in the Himalayas, Northern Pakistan was investigated in this research. Landsat MSS, TM and ETM+ images were used for this study. Digital elevation models derived from ASTER GDEM and SRTM were also utilized. Visible, infrared and thermal infrared channels were utilized in order to get accurate glacier change maps. Three methods were tried to map this debris-covered glacier in this research. The glacier has been mapped successfully and the changes in the glacier terminus from 1978 to 2011 have been calculated. Manual, semi-automatic and thermal methods were found to give similar results. It was found that the glacier has undergone serious ablation during this period despite of the fact that many of the larger glaciers in the Hindu Kush and Karakoram mountain regions in the Upper Indus Basin were reported to be expanding. The terminus has been moved back about 600 meters during this period and there was an abrupt change in the glacier terminus during 1990-2002. We propose that debris thickness is not the only factor that influences the glacier ablation but the altitude of the debris-covered glacier as well. Many glaciers in the Karakoram region reported to be expanding were having higher altitudes compared to the study area.

Glacier retreat, rock weathering and the growth of lichensin the Churup Valley, Peruvian Tropical Andes

The most heavily glacierized tropical range in the world– the Peruvian Cordillera Blanca-has been losing ice since the end of the Little Ice Age(LIA).In this study,the decline of the Churup glacier(9°28’18"S;77°25’02"W)and associated processes were documented employing multi-proxy approach including the analysis of remotely sensed images(1948-2016),the Schmidt hammer rock test and lichenometric dating.It is shown that Churup glacier has lost the vast majority of its estimated LIA extent(1.05±0.1 km^2;45.0×10^6-57.4×10^6 m^3).The rate of glacier retreat is documented to vary in space(SE,SW and NW-facing slopes)and time,with the peak between 1986 and 1995.With an area of 0.045 km^2 in 2016,it is expected that the complete deglaciation of the Churup valley is inevitable in the near future.Recently(post-LIA)exposed bedrock surfaces have shown higher R-values(54.2-66.4,AVG 63.3,STDEV 2.9)compared to pre-LIA exposed surfaces(46.1-59.3,AVG 50.1,STDEV 4.9),confirming the links to the duration of rock weathering.The Lichenometric dating is applied to recently exposed areas and elevations above 4800 m a.s.l.,revealing only limited reliability and agreement with the age of deglaciation estimated from remotely-sensed images in such an environment.

State and fate of the remaining tropical mountain glaciers in Australasia using satellite imagery

Tropical glaciers are extremely sensitive to a warming climate. In this paper, the evolution of the remaining tropical glaciers in Australasia(Irian Jaya, Indonesia) during the period 1988-2015 was quantified. Landsat series images, a digital elevation model from SRTM, and previously published data were used. Estimated total glacier area in 1988, 1993, 1997 and 2004 was 3.85 km2±0.13 km2, 3.01 km2±0.08 km2, 2.49 km2±0.07 km2 and 1.725 km2 ±0.042 km2, respectively. Only 0.58 km2±0.016 km2 glacierized area remained in 2015 in Puncak Jaya, which is about 84.9% loss in just 27 years. If this rate continued, the remaining tropical glaciers in Australasia would disappear in the 2020 s. Timeseries analysis of climate variables showed significant positive trends in air temperature(0.009°C per year) and relative humidity(0.43% per year) but no considerable tendency was observed for precipitation. Warming climate together with mining activities would accelerate loss of glacier coverage in this region.

The 2015/16 El Nino-related glacier changes in the tropical Andes

Significant changes in the area and snowline altitude of two glacierized mountains - Nevado Champara (Cordillera Blanca,Peru) and Cerro Tilata (Cordillera Real,Bolivia)- in the tropical Andes,before and after the recent El Nino in 2015/16 period,have been analysed using Sentinel 2A and Landsat data.It is seen that the recent El Nino has been accompanied by higher fluctuation in glacier coverage on Nevado Champara and the loss of glacier coverage on Cerro Tilata was very high during the past 16 years.Rise in snowline altitude of selected glaciers was very high after the 2015/16 El Nino.Increase in the area covered by snow and ice during the La Nina periods were not enough to cover the ice loss occurred during the previous El Nino events and the strongest El Nino in 2015/ 16 was followed by a significant loss of ice-covered areas in the tropical Andes.Freshwater resources in this region will be affected in the near future if the current trends in glacier decline continue.Adaptation strategies needs to be implemented to reduce the impacts of the continuing loss of glacierized on regional communities in the tropical Andean region.

Glacial Lakes in the Andes under a Changing Climate:A Review

In this article, we review the current knowledge of the glacial recession and related glacial lake development in the Andes of South America. Since the mid-1980 s, hundreds of glacial lakes either expanded or formed, and predictions show that additional hundreds of lakes will form throughout the 21 st century. However, studies on glacial lakes in the Andes are still relatively rare. Many glacial lakes pose a potential hazard to local communities, but glacial lake outburst floods(GLOFs) are understudied. We provide an overview on hazards from glacial lakes such as GLOFs and water pollution, and their monitoring approaches. In real-time monitoring, the use of unmanned aerial systems(UASs) and early warning systems(EWSs) is still extremely rare in the Andes, but increasingly authorities plan to install mitigation systems to reduce glacial lake risk and protect local communities. In support, we propose an international remote sensing-based observation initiative following the model of, for example, the Global Land Ice Measurements from Space(GLIMS) one, with the headquarters in one of the Andean nations.