Earth and space test Flashcards
The main layers (crust, mantle, core), general features of each layer
Crust: The crust is the outermost layer of the Earth, characterized by its relatively thin (5-70 km thick) and solid composition. It is divided into two types: continental crust (made up of granite rocks) and oceanic crust (composed of basaltic rocks). The crust is where all terrestrial life exists and where most geological processes, such as earthquakes and volcanic eruptions, occur.
Mantle: The mantle is the layer beneath the crust, extending from about 70 km to 2,900 km below the Earth’s surface. It is composed of solid but flowing rock material known as magma, which circulates in convection currents. The mantle accounts for the majority of the Earth’s volume and plays a crucial role in tectonic plate movement and the formation of volcanic activity.
Core: The core is the innermost layer of the Earth, consisting of two sublayers: the outer core and the inner core. The outer core is composed of liquid iron and nickel, while the inner core is solid due to high pressure. The core generates the Earth’s magnetic field and is responsible for its overall mass and density. It is thought to be about 2,900 km to 6,371 km below the Earth’s surface.
What is continental and oceanic crust, how do they interact
Continental crust is the thick, solid outermost layer of Earth that forms the continents, while oceanic crust is a thinner, denser layer that forms the ocean floors. These two types of crust interact primarily at tectonic plate boundaries.
When tectonic plates collide, the denser oceanic crust is often subducted beneath the less dense continental crust. This can lead to the formation of mountain ranges, volcanic arcs, and deep ocean trenches.
In some cases, when two plates are moving away from each other, new oceanic crust is formed through seafloor spreading. This process creates mid-ocean ridges where magma rises from the mantle and solidifies into new crust.
Overall, the interaction between continental and oceanic crust plays a crucial role in shaping the Earth’s surface and driving geological processes such as earthquakes, volcanic eruptions, and the movement of continents.
What are tectonic plates, why do they move
Tectonic plates are large pieces of the Earth’s lithosphere that float on top of the semi-fluid asthenosphere. These plates are constantly moving and interacting with each other, which leads to the formation of mountains, earthquakes, volcanoes, and the creation of new crust. The movement of tectonic plates is primarily driven by the heat and convection currents within the Earth’s mantle.
Types of tectonic plate boundaries (divergent, convergent, transform), general features of each type, including direction of movement
Divergent plate boundaries: Plates move apart from each other. This type of boundary is characterized by mid-ocean ridges, where new oceanic crust is created through seafloor spreading.
Convergent plate boundaries: Plates move towards each other. This type of boundary is characterized by subduction zones, where one plate is forced beneath the other, leading to the formation of deep ocean trenches and volcanic arcs.
Transform plate boundaries: Plates slide past each other horizontally. This type of boundary is characterized by strike-slip faults, such as the San Andreas Fault in California, where tectonic plates grind past each other.
• How do different tectonic plate boundaries form geological features (e.g. trenches, volcanoes, hot spots, etc.)
At convergent boundaries, where two plates collide, trenches are formed when one plate is forced beneath the other in a process called subduction. This friction and pressure can also trigger volcanic activity, leading to the formation of volcanoes.
At divergent boundaries, where two plates move away from each other, magma rises from the mantle to create new crust. This process forms mid-ocean ridges and volcanic activity along the boundary.
At transform boundaries, where two plates slide past each other horizontally, intense pressure can build up and cause earthquakes. These boundaries do not typically create prominent geological features like trenches or volcanoes.
Hot spots are formed by magma rising from the mantle in a fixed location above a mantle plume. As the plate moves over the hot spot, a chain of volcanic islands or seamounts can be created.
•What is this theory, what is the evidence that supports this theory (e.g. shape of landmasses matching, same fossils found in different locations, rock strata matching)
The continental drift theory suggests that Earth’s continents were once joined together in a single landmass and have since drifted apart. Evidence supporting this theory includes the matching shapes of continents like South America and Africa, the presence of the same fossils on different continents, and the matching rock layers and mountain ranges on opposite sides of the Atlantic Ocean.
Where were continents located in the past (Pangaea) and what may happen in the future
In the past, all continents were located together in a supercontinent called Pangaea. In the future, some geologists believe that all continents may eventually collide back together to form a new supercontinent, although this process would take millions of years to happen.
Explain how geological activity in the past and present affects an ecosystem (flora and fauna, and non-living things)
Geological activity in the past, such as volcanic eruptions or earthquakes, can have a significant impact on an ecosystem by altering the landscape and soil composition. This can disrupt the habitats of plants and animals, leading to changes in species distribution and diversity. Additionally, geological activity can also create new landforms, such as mountains or valleys, which can influence the flow of water and nutrients through an ecosystem.
In the present, ongoing geological processes such as erosion, weathering, and tectonic activity continue to shape the physical environment of an ecosystem. These processes can contribute to the formation of new habitats, such as river valleys or coastal cliffs, providing opportunities for different species to thrive.
Overall, geological activity plays a critical role in shaping the structure and function of ecosystems by shaping the physical environment and influencing the distribution of flora and fauna.
For example, if there is a converging plate boundary forming mountains, then flora and fauna need to develop adaptations that deal with cooler temperatures, less oxygen, more/less rainfall, overall harsh conditions - what features may develop to adapt
Adaptive features such as thick fur, large lung capacity, and water-saving mechanisms may develop in the flora and fauna to cope with cooler temperatures, less oxygen, and variable rainfall in mountainous regions.
Some species may evolve specialized feeding habits or foraging behaviors to take advantage of resources found in the rocky, rugged terrain of mountain environments.
Plants may develop deeper root systems to access moisture in the soil or store nutrients in specialized structures to survive in nutrient-poor mountain soils.
Animals may evolve larger body sizes or stronger limbs to navigate steep slopes and rocky terrain, while also developing camouflage or defensive mechanisms to avoid predators.
Mutualistic relationships may form between plants and animals to support each other’s survival in challenging mountain environments, such as pollination by specialized insects or seed dispersal by birds.
