It has been a long break since I shared a reading list. These are some interesting articles I came across in the past couple of months.
1) How a massive earthquake in Eastern India led to the birth of modern seismology. On 12th June 1897, a massive earthquake struck the Shillong Plateau and neighboring Assam causing widespread damage. Media reports were detailed but sensational. But they did push geologists towards developing a more rigorous science of earthquake monitoring and analysis. This is a fine piece of archival research by Utsa Bose, tracing the birth of the modern science of seismology. The role of the nascent Geological Survey of India with its first generation of Indian geologists is especially noteworthy.
2) NASA’s Perseverance Sets Off-World Record for Total Distance Driven. News from NASA informs us that the Mars Perseverance Rover has now traveled further than any vehicle ever has on another world. On October 11, the rover’s odometer clocked 45.22 kilometers surpassing the 45.16 km set by the Mars Opportunity Rover.
Perseverance’s wandering has taken it to the western rim of the Jezero Crater, an area known as “Lac de Charmes”.
Around the rover are some of the oldest rocks known in the solar system. The Jezero Crater was formed by an impact about 3.9 billion years ago and is filled with surficial impact debris, as well as rocks from Mar’s interior that were thrown up during the impact.
Since Mars lacks plate tectonics, rocks from its earliest history are preserved. On Earth, plate tectonics has recycled the initial crust that formed as our planet cooled. The geological trajectory followed by Mars and Earth before Earth developed plate tectonics may have been similar. These very ancient rocks from Mars gives us an analogue for understanding early earth geological processes.
But take a look and admire this info-graphic of the many rovers that have explored Earth, Moon, and Mars and given us so much exciting data to work with in the coming decades.
Source: NASA/JPL-Caltech.
3) Why Do These Fossil Shells Flip Their Spirals Every Few Millennia? Foraminifera are unicellular protists. Many species construct a coiled shell around the soft tissue. Most species may contain both right handed and left handed coiled shells. Scientists noticed that in a few species the direction of coiling is either predominantly right spiral or left spiral. And more interestingly, as they traced the species history through their fossil record, they found that the direction of coiling flipped between right handed and left handed every few thousands of years.
There are quite a few explanation put forth to explain this with changes in temperature of the sea water being a leading answer proposed in the early research of this phenomenon. But was it so? Or are we seeing speciation, the evolution of a new variant or species that then quickly spreads through the world’s oceans and becomes a common fossil shell to be discovered by paleontologists? A fascinating look at the evolution and ecology of foraminifera by Fanni Daniella Szakál.