Describe the process by which a tsunami forms. Mention the government’s preparations for and mitigation of tsunamis.
Model Answer Introduction Primary rocks, also known as igneous rocks, are formed through the solidification of molten material, either magma or lava. They are characterized by their crystalline structure and diverse mineral composition. Understanding primary rocks is crucial for insights into the EaRead more
Model Answer
Introduction
Primary rocks, also known as igneous rocks, are formed through the solidification of molten material, either magma or lava. They are characterized by their crystalline structure and diverse mineral composition. Understanding primary rocks is crucial for insights into the Earth’s geological history and the rock cycle.
Types of Primary Rocks
Granite
Granite is a coarse-grained intrusive rock primarily composed of quartz, feldspar, and mica. It is widely used in construction due to its durability and aesthetic appeal. The slow cooling of magma beneath the Earth’s surface allows for the formation of large crystals, giving granite its distinctive texture (Source: “Geology: A Very Short Introduction” – Simon & Schuster).
Basalt
Basalt is a fine-grained extrusive rock rich in iron and magnesium. It forms when lava cools rapidly at or near the Earth’s surface, resulting in small crystals. Basalt is commonly found in volcanic areas and is used in road construction and as a building material (Source: “Igneous Rocks” – USGS).
Obsidian
Obsidian is a volcanic glass formed from the rapid cooling of lava. It is known for its smooth texture and shiny appearance, making it popular for decorative purposes and historically used as a cutting tool in ancient civilizations (Source: “The Rock Cycle” – Geological Society of America).
Characteristics of Primary Rocks
Formation
Primary rocks are formed through the solidification and crystallization of molten magma or lava, making them the first rocks to form in the Earth’s crust.
Mineral Composition
These rocks typically contain minerals like quartz, feldspar, mica, and amphibole. The specific minerals present depend on the chemical composition of the original magma.
Texture
Primary rocks exhibit a range of textures, from fine-grained to coarse-grained, determined by the cooling rate of the magma. Rapid cooling results in fine-grained textures, while slow cooling leads to coarse-grained textures.
Crystal Size
Due to slow cooling, primary rocks often contain large, well-formed crystals visible to the naked eye, providing insights into their formation history.
Interlocking Structure
They have an interlocking crystalline structure that enhances strength and durability, with individual mineral grains tightly interconnected.
Lack of Fossils
Primary rocks do not contain fossils or organic remains, as they are formed from molten material.
Intrusive and Extrusive Forms
Primary rocks are classified into intrusive (formed beneath the surface) and extrusive (formed at the surface), affecting crystal size and texture.
Conclusion
Primary rocks are crucial components of the Earth’s crust, offering valuable insights into geological processes and the planet’s history. Their diverse types and characteristics help in understanding the formation and evolution of the Earth’s crust over time.
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According to WMO(World Meteorological Organization)- "Tsunami is a series of waves generated in a body of water by the displacement of large volume of water, usually as a result of earthquakes, landslides or volcanic eruptions". Formation of Tsunami - Displacement of water through earthquake, landslRead more
According to WMO(World Meteorological Organization)- “Tsunami is a series of waves generated in a body of water by the displacement of large volume of water, usually as a result of earthquakes, landslides or volcanic eruptions”.
Formation of Tsunami –
Tsunami preparedness involves –
Mitigation Efforts taken by the governments –
- Creation of institutional framework like NDMA,INCOIS,IMD,NCMRWF.
- Coastal radar and surveillance system for early warning system.
- Tsunami resistant construction at Andaman and Nicobar islands .
- Regulatory measures like Disaster Management Act 2005 , Coastal Regulation Zone etc .
- Creation of Intergovernmental Oceanographic Commission (IOC),Sendai framework for Disaster Risk Reduction 2005 etc to promote international cooperation .
- Formation of National Disaster Response Force (NDRF).
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