Friday, February 19, 2021

Fossil Dickinsonia in Bhimbetka Sandstones: Nature India Article

 My short piece published in Nature India on the surprising report of Ediacaran age fossil Dickinsonia in the Bhimbetka caves near Bhopal, Central India, and its geological and biological significance.

an excerpt:

"The biological affinity of Dickinsonia is controversial. Most scientists tend to accept it as an early animal. Some like Gregory Retallack, co-discoverer of this fossil, think of it to be a large algae or lichen. He argues that the mainstream view that Dickinsonia was a marine animal is based on weak evidence, while his own detailed work shows that Dickinsonia was a land creature, forming biogenic crusts on soils. Interestingly, the Bhimbetka rocks were deposited in a mostly terrestrial setting, more in alignment with Retallack's interpretation. Importantly for geology, its restricted time span, being found only in rocks between 555-550 million years old, makes it a diagnostic age indicator. So far, no animal fossils have been found in the Vindhyan rocks. This finding may inspire geologists to start searching contemporaneous Indian basins afresh for such subtle clues".

Fossil from dawn of animal life found in India’s famous caves.

Wednesday, February 17, 2021

Readings: Chamoli Debris Flow Disaster, Uttarakhand

The Himalaya are geologically and ecologically fragile. Despite this, the Indian government has repeatedly ignored advice from its scientists and has gone ahead with major infrastructure projects, which have not been assessed rigorously for the inevitable impact they will have on the surrounding environment, people and livelihoods.

The February 7 2021 Chamoli debris flow that destroyed two dams and killed scores of people with hundreds still missing is the latest example of how the natural tendency of Himalayan slopes to fail combines with steel and concrete to cause enormous damage. 

Here is a short list of readings of this event and Himalaya infrastructure projects.

1) Dr. Dave Petley has put together a sequence of events based on crowd sourcing satellite imagery. This was a remarkable example of experts collaborating to pinpoint the location and cause of this debris flow within just a day. 

The catastrophic landslide and flood in Chamoli in Uttarakhand: the sequence of events.

 2) M. Rajshekar explores the messianic drive of the Central and the Uttarakhand government to build dams in the Himalaya. 

Modi said he would revive Ganga but his government is doing the opposite by reviving dams

3) R.Shreedhar, an experienced earth scientist working in the Himalaya writes a fine essay about the neglect of science and the political economy of Himalaya dam building.

The Science and the Political Economy of the Rishi Ganga Flood.

4) The title of this essay by Nivedita Khandekar says it all.. "We have learnt nothing from the 2013 Uttarakhand Disaster".

We have learnt nothing from 2013 Uttarakhand disaster.