Monday, August 21, 2023

Darwin's Earthworms, Ocean Currents, Geology Heritage Lost

My latest set of readings.

1) Why Darwin Admired the Humble Earthworm. A delightful essay by Philip Ball on Darwin's work on earthworms. Published towards the end of his career, this book apparently sold more copies than the Origin of Species! As Philip Ball wittily observes, that tells us something about the English passion for gardening. Darwin's research on earthworms consisted of detailed observations and cleverly designed experiments, often carried out with the help of family members. 

His powers of observation and analysis remained undimmed - "Darwin reported that 80 percent of leaves he removed from worm burrows had been inserted tip first—a far from random distribution".

2) No, the Gulf Stream isn't going to shut down. The premise of the movie The Day After Tomorrow is that of a catastrophic cold snap engulfing north America and Europe, triggered by the shutting down of the Gulf Stream. This massive ocean current forms in the subtropics in the western side of the Atlantic and transports heat from the lower latitudes to northern Europe, moderating the temperatures in these northern regions. Media reports claim that recent work might be pointing to a collapse of the Gulf Stream, but as Frank Jacobs explains, people are conflating two very different current systems. 

Some studies are suggesting that the Atlantic Meridional Overturning Circulation, a much smaller and restricted circulation system, might be slowing down and might even collapse by 2050. This will result in some cooling in the Greenland and Norwegian seas, but will not affect the larger Gulf Stream. The article has a nice animation of global ocean currents which I found informative.

3) They Have Put Geology in Coffins. For long, geologists have been complaining about the utter indifference shown by successive Indian governments to our natural heritage. Here is one more example from Himachal Pradesh. Along the Kalka-Shimla highway, on the stretch between Parwanoo and Solan lay a treasure. This was a section of sedimentary rocks recording the retreat of the Tethys Sea which began after the collision between India and Asia started creating high topography. Along this stratigraphic section, marine sediments give way to freshwater deposits. The outcrop was a natural outdoor laboratory for students and researchers. Now it is gone. The National Highway Authorities of India has covered it with concrete and stone walls. Science is the big loser again. 

Arundeep Ahluwalia expresses the anguish of geologists who knew and loved this part of the Himalaya- "It forever denies coming generations any chance to study the long stretches of such highways and to the nature lovers in society the excitement of the history and grandeur of the earth".  

Read and weep. 

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