Timing of avalanche activity that triggered devastating flood in the Dhauliganga valley of Chamoli district in Uttarakhand on February 7, 2021 has been ascertained on the basis of the record of broad-band seismic stations at Tapoban and other places by the scientists of Dehradun based Wadia Institute of Himalayan Geology. The same has been published recently in Nature Scientific Reports. Based on high frequency signals recorded continuously around 2.30 hours before the avalanche activity the authors have suggested the use of seismic monitoring for avalanche warning.
Journalistic enthusiasm
Taking lead from the authors a number of vernacular newspapers have questioned disaster managers for not utilising this and similar research outputs for warning the population likely to be affected and saving human lives.
Post-disaster correlations
Analysis and correlation of even seemingly unrelated data from various sources is a commonplace amongst scientific community after most major disaster incidences. This has time and again brought forth distinct anomalies and this is true even for earthquakes. Leave apart abnormal animal behavior higher land surface temperature (LST) anomalies have been reported for Mw 6.3 April 6, 2006 L’Aquila earthquake (Italy), Mw 7.8 April 25, 2015 Gorkha Earthquake (Nepal), Mw 8.3 September 16, 2015 Illapel Earthquake (Chile), Mw 7.5 October 26, 2015 Hindu Kush Earthquake (Afghanistan). Both mid-infrared (MIR) luminescence and thermal infrared (TIR) anomalies have been reported for Mw 7.6 January 26, 2001 Bhuj Earthquake (India) and Mw 6.5 August 8, 2017 Ziuzhaigou Earthquake (China). A number of reports related to electromagnetic anomaly, gas emissions, groundwater level changes, pattern of foreshocks and others are also available for various earthquakes around the world.
Despite these scientific observations earthquake prediction has been eluding researchers, largely due to non-uniformity in these precursors.
Avalanche prediction
The authors have suggested use of high frequency seismic signals for predicting avalanche activity. The authors would however agree that avalanche is a commonly occurring phenomenon in the Higher Himalayas and the recorded high frequency seismic signals would have gone unnoticed had these not resulted in Dhauliganga tragedy.
Moreover, it is yet to be established that all anomalous high frequency seismic signals result in avalanche activity.
To add to it no one can say with desired confidence level that a particular avalanche is to result in a Dhauliganga-like catastrophic flood.
The above cited concerns are really pertinent and unless these are satisfactorily addressed and unanimously agreed by the scientific community, it seems little premature to suggest something to be taken care of by the disaster managers.
Warning dissemination
As regards dissemination of the warning, the authors as also others would agree that (i) occurrence time window, (ii) location likely to be impacted, and (iii) expected magnitude of the hazard have to be ascertained for utilising any system for warning the masses. At the same time there has to be high degree of confidence in the system utilised for generating the warning, and the chances of unpredictable random events have also to be ascertained.
Most importantly probability of missed events and false alarms has to be ascertained with high degree of confidence as the former could result in loss of lives and property while the latter could cause mass panic.
There are no issues really with the scientific research and the same should go on for larger good of the humanity. The techniques and systems have however to be validated scientifically and tested in the field for efficacy before being utilised for issuing public warnings.
Narrowing monitoring
As put forth by the authors Uttarakhand has 1573 glaciers covering an area of around 436 sq km and an avalanche can trigger around any of these.
Moreover monitoring of the Higher Himalayan region is severely constrained by access, weather and connectivity and no agency can undertake real time monitoring unless the authors with their scientific understanding identify potentially dangerous zones with Dhauliganga-like flood potential.
To conclude
In the end it is put forth that the authors have repeatedly characterised rock-ice avalanche as being deadly and ensuing flash flood as being devastating. Contrary to that, we would call the flash flood as being deadly or devastating.
And the journalists are advised to gather information on practical application of scientific research for it takes long to translate research findings into practically usable apparatus. Lack of that could propagate a wrong message and discourage individuals who are toiling hard to improve the scenario.
Very practical thought, however without characterising the causative mechanism we can not able to understand it. Let us hope soon one day geoscience research will trickle down to grass root level to mitigate the hazard.