Researchers have recently discovered that rainfall plays a rather significant role in shaping mountainous regions. The scientists used high-end technology to precisely detect how mountains are impacted by raindrops and helped solve a long-standing scientific mystery.
The University of Bristol research team has accurately analyzed precipitations’ effect, showing how mountains have evolved throughout eons. The Himalaya-focused study has also unveiled more about the consequence of intentional warming of the planet, as well as how humans around these magnificent landscapes cope with the changes.
Rainfalls Impact Mountainous Structures
The research team overcame a difficulty other scientists have previously faced – creating accurately-enough models to test the most significant factors involved.
Dr. Byron Adams, the study’s lead author, together with Arizona State University and Louisiana State University researchers, decided to use cosmic clocks within sand grains to precisely measure how quickly rivers can erode their banks.
Dr. Adams said: “When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hill slopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding.”
According to the researcher, it may seem rather intuitive that more rain is able to shape mountains ‘by making rivers cut down into rocks faster.’ However, experts have also believed rain can erode a landscape sufficiently rapid to basically ‘suck’ the rocks out of the soil, effectively pulling mountains up at a rather accelerated pace.
The Erosion Could be Dangerous
Still, these theories have been argued for numerous years because the measurements required to prove them are incredibly intricate. And that is exactly what makes this breakthrough such an exciting finding, as it steadily supports the concept that atmospheric and solid Earth processes are deeply connected.
The study was carried out in Bhutan and Nepal because geologists consider this region one of the most sampled landscapes for erosion rate research. The success of the study is also a result of the team overcoming one significant issue when merging regression methods with numerical models of how rivers erode.
Dr. Adams explained: “We tested a wide variety of numerical models to reproduce the observed erosion rate pattern across Bhutan and Nepal. Ultimately only one model was able to accurately predict the measured erosion rates. This model allows us for the first time to quantify how rainfall affects erosion rates in rugged terrain.”
Researchers hope this study will be in the advantage of land use management and infrastructure maintenance in the Himalaya region but not only. There’s the constant hazard that high erosion rates will dramatically advance sedimentation behind dams, putting at risk vital hydropower projects in the world’s highest mountain chain.
The author of the study also believes increased rainfall could weaken hill slopes; this enhances the danger of debris flows or landslides, some of which may be massive enough to clog rivers, creating a new hazard: lake outburst floods.