I need help with two questions.
68.An igneous rock like granite can change into a very different sedimentary rock like sandstone. What processes must have acted on the granite over the years to change this igneous material into sedimentary rock?
19. Much of the information taught in Earth-Space Science would not be available if it weren’t for our remote sensing abilities. List two topics discussed in our course and explain how our remote sensing strategies contribute to our knowledge of these topics.
68. To understand how an igneous rock like granite can change into a sedimentary rock like sandstone, there are a few processes that must have acted on the granite over the years. Here are the steps involved in this transformation:
1. Weathering: Weathering involves the breakdown of rocks into smaller fragments through physical processes like freeze-thaw cycles, abrasion by wind and water, and chemical processes like dissolution and oxidation. In the case of granite, weathering gradually breaks it down into smaller pieces called sediment.
2. Erosion: Erosion refers to the transportation of sediment by natural agents such as wind, water, and glaciers. The sediment derived from weathered granite is carried away from its original location and transported to new areas.
3. Deposition: When the transporting agents lose energy, they deposit the sediment they were carrying. This deposition occurs in environments like rivers, lakes, and oceans where the sediment settles and accumulates over time. The deposited sediment is typically composed of various minerals, including those derived from granite.
4. Lithification: After deposition, the buried sediment undergoes lithification, which involves compaction and cementation. Compaction occurs as the weight of the overlying sediments compresses the layers beneath, reducing the pore spaces between particles. Cementation occurs when minerals precipitate from groundwater and fill the remaining pore spaces, binding the sediment particles together to form solid rock.
Over millions of years, these processes can transform the igneous rock, such as granite, into a sedimentary rock like sandstone. The original minerals from the granite may remain in the sandstone to some extent, but the overall texture and composition of the rock change significantly.
19. Remote sensing plays a crucial role in Earth-Space Science by providing valuable information about various topics. Here are two topics discussed in the course along with explanations of how remote sensing strategies contribute to our knowledge of these subjects:
1. Climate Change: Remote sensing allows scientists to monitor changes in Earth's climate system from a global perspective. Satellites equipped with specialized sensors can measure various parameters such as sea surface temperatures, atmospheric conditions, vegetation health, and changes in ice cover. By collecting data over extended periods, remote sensing helps researchers observe long-term climate trends, identify patterns, and understand the impacts of climate change on different regions of the planet.
2. Land Cover and Land Use: Remote sensing enables us to monitor and evaluate changes in land cover and land use over time. By using satellite imagery and other remote sensing data, scientists can assess deforestation, urban expansion, agricultural practices, and changes in natural habitats. Remote sensing techniques provide accurate and detailed information on land cover classification, allowing for better management of resources, land-use planning, and environmental conservation.
In summary, remote sensing strategies contribute to our understanding of climate change by monitoring global parameters and providing long-term data. They also help us assess land cover and land use changes, supporting sustainable land management practices and conservation efforts.