UGC NET Geography 1

The north-pole lies with in the Arctic Ocean whereas south-pole is located within Antartic Continent. Which of the following theory uses this phenomenon as a supportive argument ?

(A) Theory of Isostasy

(B) Theory of Plate Tectonics

(D) Tetrahedral Theory

The answer is **(B) Theory of Plate Tectonics**.

The theory of plate tectonics states that the Earth's surface is made up of a number of large plates that are constantly moving. The North Pole lies within the Arctic Ocean because the Arctic Ocean is located on a plate that is moving away from the North Pole. The South Pole, on the other hand, is located within Antarctica because Antarctica is a continent that is not moving.

The other theories listed are not supportive of this phenomenon. The theory of isostasy states that the Earth's crust is balanced by the underlying mantle, so the North Pole would not be located in an ocean if this theory were correct. The theory of convective current theory states that the Earth's mantle is heated from below and that this heat causes the mantle to move, but this theory does not explain why the North Pole is located in an ocean and the South Pole is located on a continent. The tetrahedral theory is not a scientific theory and is not supported by evidence.

**Explanation of other theories:**

* **Theory of Isostasy** states that the Earth's crust is balanced by the underlying mantle. This means that the weight of the crust is supported by the mantle, so the crust does not sink into the mantle. The North Pole is located in an ocean because the crust in this area is relatively thin. The mantle is therefore able to push up the crust, creating an ocean.

* **Theory of Convective Current Theory** states that the Earth's mantle is heated from below and that this heat causes the mantle to move. The mantle is a layer of hot, solid rock that lies below the Earth's crust. The heat from the Earth's core causes the mantle to move in a convective current. This means that the mantle is constantly circulating, with hot material rising to the surface and cooler material sinking to the bottom. The convective current theory does not explain why the North Pole is located in an ocean and the South Pole is located on a continent.

* **Tetrahedral Theory** is not a scientific theory and is not supported by evidence. This theory states that the Earth is shaped like a tetrahedron, with the North Pole at one point of the tetrahedron and the South Pole at another point. The theory also states that the Earth's crust is made up of four plates that are constantly moving. However, there is no scientific evidence to support this theory.

Therefore, the theory of plate tectonics is the best explanation for why the North Pole lies within the Arctic Ocean and the South Pole is located within Antarctica.

🌍

Comments

geostationary and sun-synchronous

Orbital characteristics of Remote sensing satellite geostationary and sun-synchronous Orbits in Remote Sensing Orbit = the path a satellite follows around the Earth. The orbit determines what part of Earth the satellite can see , how often it revisits , and what applications it is good for . Remote sensing satellites mainly use two standard orbits : Geostationary Orbit (GEO) Sun-Synchronous Orbit (SSO) Geostationary Satellites (GEO) Characteristics Altitude : ~35,786 km above the equator. Period : 24 hours → same as Earth's rotation. Orbit type : Circular, directly above the equator . Appears "stationary" over one fixed point on Earth. Concepts & Terminologies Geosynchronous = orbit period matches Earth's rotation (24h). Geostationary = special type of geosynchronous orbit directly above equator → looks fixed. Continuous coverage : Can monitor the same area all the time. Applications Weather...

Disaster Management

1. Disaster Risk Analysis → Disaster Risk Reduction → Disaster Management Cycle Disaster Risk Analysis is the first step in managing disasters. It involves assessing potential hazards, identifying vulnerable populations, and estimating possible impacts. Once risks are identified, Disaster Risk Reduction (DRR) strategies come into play. DRR aims to reduce risk and enhance resilience through planning, infrastructure development, and policy enforcement. The Disaster Management Cycle then ensures a structured approach by dividing actions into pre-disaster, during-disaster, and post-disaster phases . Example Connection: Imagine a coastal city prone to cyclones: Risk Analysis identifies low-lying areas and weak infrastructure. Risk Reduction includes building seawalls, enforcing strict building codes, and training residents for emergency situations. The Disaster Management Cycle ensures ongoing preparedness, immediate response during a cyclone, and long-term recovery afterw...

Linear Arrays Along-Track Scanners or Pushbroom Scanners

Multispectral Imaging Using Linear Arrays (Along-Track Scanners or Pushbroom Scanners) Multispectral Imaging: As previously defined, this involves capturing images using multiple sensors that are sensitive to different wavelengths of electromagnetic radiation. Linear Array of Detectors (A): This refers to a row of discrete detectors arranged in a straight line. Each detector is responsible for measuring the radiation within a specific wavelength band. Focal Plane (B): This is the plane where the image is formed by the lens system. It is the location where the detectors are placed to capture the focused image. Formed by Lens Systems (C): The lens system is responsible for collecting and focusing the incoming radiation onto the focal plane. It acts like a camera lens, creating a sharp image of the scene. Ground Resolution Cell (D): As previously defined, this is the smallest area on the ground that can be resolved by a remote sensing sensor. In the case of linear array scanne...

Discrete Detectors and Scanning mirrors Across the track scanner Whisk broom scanner.

Multispectral Imaging Using Discrete Detectors and Scanning Mirrors (Across-Track Scanner or Whisk Broom Scanner) Multispectral Imaging: This technique involves capturing images of the Earth's surface using multiple sensors that are sensitive to different wavelengths of electromagnetic radiation. This allows for the identification of various features and materials based on their spectral signatures. Discrete Detectors: These are individual sensors that are arranged in a linear or array configuration. Each detector is responsible for measuring the radiation within a specific wavelength band. Scanning Mirrors: These are optical components that are used to deflect the incoming radiation onto the discrete detectors. By moving the mirrors, the sensor can scan across the scene, capturing data from different points. Across-Track Scanner or Whisk Broom Scanner: This refers to the scanning mechanism where the mirror moves perpendicular to the direction of flight. This allows for t...

Vineesh V, Geography

Search This Blog