Comprehensive Year 8 Geography Arctic Environment and Tectonics Revision Notes
Location and Geography of the Arctic Region
The Arctic Region is primarily located in the Northern Hemisphere, with the majority of the region found within the boundaries of the Arctic Circle. The Arctic Circle is situated at approximately North latitude. This vast region encompasses several countries, including parts of the United States (Alaska), Canada, Russia, Norway, Sweden, Finland, and Iceland. Additionally, Greenland is a significant part of the Arctic region; while it is not an independent country, it is a territory belonging to Denmark. A unique aspect of the Arctic's geography is the North Pole and the surrounding Arctic Ocean, which, under international law, are not owned by any single nation. This lack of ownership remains because the North Pole is comprised of shifting sea ice rather than a permanent continental landmass that can be claimed as sovereign territory.
Landscape, Environment, and Climate of the Arctic
The Arctic environment is defined by distinct biological and geological features, specifically the tundra and permafrost. The tundra is a cold, treeless biome characterized by its harsh climate and low-growing vegetation. Beneath the surface of much of this region lies permafrost, which is defined as ground that remains permanently frozen for at least two consecutive years. The Arctic climate is characterized by significant seasonal variations. For example, temperature and rainfall patterns are often visualized through climate graphs where blue bars represent rainfall and a red line represents temperature. In typical Arctic climate data, temperatures in March can remain well below freezing, while rainfall in May is generally low, reflecting the arid nature of these cold environments.
Animal Adaptations in the Arctic
Animals inhabiting the Arctic have developed specialized physical and behavioral adaptations to survive extreme cold. Many species, such as the Arctic Fox, possess thick fur or dense feathers that trap heat and provide essential insulation. Others, such as the Polar Bear, rely on blubber, which is a thick layer of fat stored under the skin that helps retain body heat and serves as an energy reserve. Camouflage is another critical adaptation; animals like the Polar Bear and the snowshoe hare undergo seasonal changes in coat color to blend into snowy or rocky environments, helping them evade predators or stalk prey. Behavioral adaptations include hibernation or migration, where animals like Caribou or Reindeer either sleep through the winter months or move to warmer areas to avoid the harshest weather conditions.
Impact of Global Warming on Arctic Inhabitants
Global warming presents a complex mixture of challenges and opportunities for people living in the Arctic. Negative impacts include the loss of traditional hunting grounds as melting ice makes it difficult for indigenous populations to hunt seals and other marine animals. This leads to a decrease in available food from natural sources, forcing residents to rely on expensive food imported from distant locations. Conversely, there are positive impacts associated with a warming climate. Melting ice opens up new shipping routes, making it easier for boats to travel through the Arctic to deliver supplies or facilitate travel. Furthermore, rising temperatures may create more opportunities for agriculture, allowing for the growth of plants and vegetables that were previously unable to survive in the region, thereby increasing access to fresh food.
Tourism and Its Environmental Consequences
Tourism in the Arctic is driven by diverse motivations, including the desire for relaxation, the opportunity to see historical sites, experiencing different climates, trying new foods, and witnessing unique cultures. However, large-scale tourism, such as cruise liner arrivals, brings both benefits and problems. For instance, the cruise liner Grand Princess, which can carry up to passengers, often visits Honningsvåg in Northern Norway, a town with a population of only . Benefits include job creation, economic growth, and increased awareness of climate and conservation issues. On the negative side, tourism causes pollution from ships and individuals, littering, the scaring of local wildlife, and physical damage to the fragile environment. General environmental damage caused by tourists includes the trampling of plants, excessive use of water and energy by hotels, and air pollution from planes and buses.
Structure of the Earth and Plate Tectonics
The Earth is composed of four distinct layers: the crust, mantle, outer core, and inner core. The crust is further divided into oceanic and continental types. The oceanic crust is composed of basalt, is relatively thin with an average thickness of , and is heavier than continental crust. The continental crust is primarily made of granite, is thicker at an average of , and forms the Earth's landmasses. The crust and the uppermost part of the mantle together form the lithosphere. Below this, the mantle contains hot, soft rock that moves in convection currents. These currents act like a conveyor belt, dragging the lithospheric plates above them. This movement is slow, typically a few centimeters per year; however, over long periods, it results in massive changes, such as the Indian plate moving north over the last million years.
Tectonic Plate Boundaries and Seismic Activity
Earthquakes and volcanoes are primarily located along tectonic plate boundaries due to the buildup of pressure from friction. At constructive plate boundaries, two plates pull apart, and magma rises from the mantle to create new ocean floor, resulting in both earthquakes and volcanoes. Destructive plate boundaries occur where two plates push together; the heavier oceanic crust is pulled down under the continental crust into the mantle in a process known as subduction. This occurs at places like the Nazca and South American plates, forming ocean trenches and mountain ranges like the Andes. Collision plate boundaries involve two continental plates pushing together, forcing rock upwards to form mountains and causing earthquakes, though typically without volcanoes. Conservative plate boundaries occur where two plates slide past each other, leading to significant pressure release as earthquakes, but no volcanic activity.
Earthquake Protection and Safety Measures
Buildings can be engineered to withstand seismic activity through several specialized techniques. These include the installation of rubber shock absorbers in the foundations to dampen vibrations, the use of cross-bracing steel structures, and triangular-shaped reinforcements to increase stability. Additionally, flexible walls are designed to bend rather than crack during a tremor. For personal safety during an earthquake, the "Drop, Cover, and Hold On" protocol is recommended: drop to hands and knees, cover the head and neck, and hold onto a sturdy shelter. If indoors, people should stay away from furniture, windows, and lamps. If outdoors, they should move away from buildings, walls, and power poles. If driving, one should stop in a safe place, use hazard lights, and remain inside the vehicle.
The Hydrological Cycle and Flooding
The hydrological cycle encompasses several key processes that move water through the environment. Precipitation includes rain, hail, sleet, or snow falling from clouds. Condensation is the cooling of water vapor into clouds. Evaporation occurs when the sun heats water from the sea, turning it into vapor. Transpiration is a similar process where water is released from plant leaves into the air. Surface run-off occurs when water flows over the ground, while groundwater flow refers to water moving through rocks and soil underground. Flooding is caused by both physical and human factors. Physical causes include heavy rainfall, steep slopes, and impermeable rock surfaces. Human causes include urbanisation, deforestation, and the construction of houses on natural floodplains.
Flood Management Strategies
Flood management is divided into soft and hard engineering techniques. Soft engineering includes afforestation (planting trees to absorb water), wetland restoration (creating "sponges" to soak up water), and floodplain zoning (restricting building on high-risk land). Examples include trees along the River Severn and wetland restoration in the New Forest. Hard engineering involves man-made structures like levees (raised banks), dams (barriers that create reservoirs like the Three Gorges Dam in China), and flood barriers (movable gates like the Thames Barrier in London). While hard engineering provides high levels of protection, it is often expensive to maintain and can disrupt local ecosystems.
Population Distribution and Migration
Population distribution describes how people are spread across a country or the world. Densely populated areas have many people living close together, while sparsely populated areas have very few residents. People generally choose to live in flat areas with good water supplies, fertile soil, and job opportunities. Conversely, they avoid mountainous land, extremely dry or cold climates, and areas prone to natural hazards. Migration is driven by push factors (reasons to leave a place, such as lack of jobs) and pull factors (reasons to move to a new place, such as better weather). Climate change is an increasingly important factor in migration; for example, rising sea levels are forcing people to leave Tuvalu, while drought and desertification in Sub-Saharan Africa make it impossible for people to farm or find water.