As reported on October 17, 2020 a team of researchers from the University of Bristol have found that rainfalls could result in the moving of mountains in their study. The discoveries made by the team during this study could possibly help geologists study the impact of rains on mountains. It could also help them study the process that is responsible for development of peaks and valleys over centuries.
The study, which was titled ‘Climate controls on erosion in tectonically active landscapes’ was published in the journal Science Advances. This study was conducted in central and eastern Himalaya of Bhutan and Nepal as these regions are currently some of the most sampled landscapes for erosion-rate studies.
The study was led by lead author Byron Adams of the University of Bristol, with ASU collaborators Whipple, Heimsath and Hodges, and with Adam Forte of Louisiana State University. They made use of cosmic clocks within sand grains to measure the speed at which rivers were eroding the rocks beneath them.
Adams explained the concept based on which they had conducted this study. He stated that there are rare element formations in some atoms within each sand grain. These formations are caused by collision of some of these atoms with cosmic particles from outer space. All of these events take place when the sand grains at the hillslopes move towards the river. They took bags of sand as samples for calculating the amount of time the sand had been there. This helped them determine the erosion rate for that particular landscape.
They planned on following this method to calculate the erosion rates all over the mountain range and further determine variations in river steepness and rainfall. The drawback in this method was that it was difficult to produce the data points and the statistical interpretations were also complex.
The team combined various regression techniques with numerical models based on the river erosions and finally developed one model which was able to predict the estimated erosion rates with high accuracy.
Whipple stated that the findings showed how rainfall counts as an important factor while monitoring tectonic activity using topography. These discoveries would also help to further study how the climate-driven erosion at the surface could control the amount slip rate on tectonic faults.
The findings are also essential for performing various activities like land-use management, infrastructure maintenance and identifying hazards in the Himalayan region.
Rainfall-driven variations in erosion rates could heavily impact the landscapes by creating instabilities and potential hazards which could affect various hydropower projects across the Himalayan region. In addition to this, there are risks of debris flow and landslides which could further clog the river, resulting in ‘lake outburst floods’.
Adams stated that the discoveries made as part of this study could help in analysing mountainous landscapes similar to the Himalayan region and help identify the hazards that could impact the entire population that resides within and at the foot of the mountains.
Whipple said that the team plans on testing the developed model on various additional data sets gathered from central and western Himalayan region in order to determine the erosion rate patterns for the entire range.