Geophysics

Geophysics

By Aditya Kapur

Geophysics is that branch of physics which is concerned with the processes and properties of earth and its surroundings. It includes the study of topics such as the shape of the earth, the gravitational and magnetic fields of earth and the plate tectonic theory and related phenomena. A scientific discipline such as geophysics links together multiple scientific fields to help develop a better understanding of a certain idea. For example, it would be very hard to explain the formation or activity of volcanoes simply in terms of geology or physics or mathematics but the integration of both subjects helps develop a more holistic theory on the working of volcanoes. Thus, an interdisciplinary science integrates and compiles two or more sciences to further enhance the study of the subject.

The subject has been historically important as it helps enhance our understanding of the earth. In 4th century BCE China, inventors were able to develop a magnetic compass which helped in navigation and a few centuries later were able to build steel needle compasses which could be used for sea navigation. In the early 1st century CE, Chinese inventor and scientist Zhang Heng built a seismoscope, a landmark achievement at the time. “This instrument was designed to drop a bronze ball from the mouth of a dragon into the mouth of a toad. By looking at which of eight toads had the ball, one could determine the direction of the earthquake.” Around 1500 years later, William Gilbert further explained the working of a compass by concluding that the earth also possessed a magnet within itself. Such discoveries and inventions play an imperative role in our lives and have stemmed from deeper integration of the sciences.

  “The influence of Sun and distant stars on the environment can be studied during the cyclic changes in the Sun as well as episodic changes in the environment due to the effect of other celestial objects in between (the) Sun-Earth environment. It is evident that if a short term changes in the sun-earth weather due to eclipse can influence the environment of the earth temporarily it can be a possible key of climate change due to abnormal solar behaviour. Recent researches have projected the change in earth’s ecosystem due to climate change which needs to be reconsidered based on the parameters of changing extra terrestrial activities of Sun-Earth system.”

-Saumitra Mukherjee, Professor, School of Environmental Sciences, Jawaharlal Nehru University

Many in the scientific community believe that there are multiple geophysical factors which contribute to global warming and climate change. These issue can be tackled through geophysical concepts. An example of this is that of combating climate change by increasing ocean alkalinity. All oceans and seas are major carbon sinks as they harbour large quantities of bicarbonate ions. Due to this property, these water bodies absorb approximately 25% of the carbon dioxide emissions. This has exponentially increased the process of ocean acidification.(the ongoing decrease in the pH of the Earth’s oceans, caused by the uptake of carbon dioxide from the atmosphere.) Ocean acidification wreaks havoc for marine life as they will not be able to survive at lower pH values of water. While the oceans can naturally neutralise carbon dioxide, they cannot manage the sharp rise in carbon emissions and the process of neutralisation could take upto a 1000 years. Thus, the only solution is to increase ocean alkalinity so as to speed up the process of neutralisation. This can be done by enhanced weathering of limestone in coastal areas and by promoting mineral dissolution in these water bodies.

Thus, geophysics can be used to combat climate change and develop more sustainable industries in order to protect the geophysical properties of our planet.