The fundamentals of physical geography, geology, and the Earth’s composition, including tectonic plates and volcanoes, play a crucial part in understanding various geological phenomena. These subjects not only form the bedrock for preliminary studies but also shed light on significant geophysical phenomena, such as the role of magma in creating volcanoes, the different layers in earth composition, and the effects of tectonic plates movement.
A Recent Study by NCPOR
The National Centre for Polar and Ocean Research (NCPOR), a Goa-based research institute, recently conducted a study that provides new insights into the functioning of the Earth’s tectonic plates. Established on May 25, 1998, NCPOR serves as India’s nodal organization responsible for coordinating and implementing the Indian Antarctic Programme.
About NCPOR
NCPOR is an autonomous Research and Development Institution under the Ministry of Earth Sciences. Its primary duty includes year-round maintenance of the two Indian stations, Maitri and Bharati, in Antarctica which were established in 1989 and 2011 respectively.
The Study’s Findings
The study focuses on the movement of tectonic plates over the lithosphere. It examines situations where the upward force of the magma is insufficient to pierce through the lithosphere, resulting in the material being deposited at sub-lithospheric depths. When the tectonic plates move, they tend to drag this deposited material along with them. Scientists carried out this study using samples of igneous rocks collected from near the Ninety East Ridge in the Indian Ocean during an expedition under the International Ocean Discovery Program (IODP).
Investigation and Results
Upon observation, scientists discovered that some basaltic samples bore similar compositions to those released by the Kerguelen hotspot. Interestingly, the minimum age of these samples was about 58 million years, younger than the adjacent oceanic crust surrounding the Ninety East Ridge, which is approximately 82-78 million years old. The study suggests that the northward-moving Indian Tectonic Plate dragged a considerable amount of Kerguelen plume material for more than 2,000 km underneath the Indian lithosphere.
Earth’s Crust and Composition
The Earth’s crust, mantle, and core make up its composition. The crust is the outermost layer and can be divided into two parts: the less dense ‘sial’ and the denser, basaltic ‘sima.’ The mantle, located beneath the crust, extends roughly 2900 km and is divided into an upper and lower layer. The asthenosphere, present in the upper mantle, provides lava for volcanic eruptions. Finally, the core comprises the inner and outer core, contributing to 16% of the Earth’s volume but 33% of its mass.
UPSC Civil Services Previous Year Question
In 2018, the Barren Island volcano was a topic on the UPSC Civil Services exam. The question required knowledge about the location and previous eruptions of this active volcano situated in the Andaman and Nicobar Islands of India. It’s worth noting that while the volcano erupted massively in 1991, there have been smaller eruptions every couple of years, with the latest recorded in February 2016.
