Change in the frequency and impact of tectonic hazards: The number of natural disasters has increased over time, but the increase in earthquakes and volcanic eruptions is less pronounced. On average there are now 30 volcanic eruptions and earthquakes a year....
Include mitigation and adaption strategies, together with assessment of risk and resilience. ACs are more able to invest in the most advanced protection and often expertise is sent to LIDCs. Volcanic Management: Prediction: • Remote sensing (long term changes, crater,...
Prediction: Currently no reliable way to accurately predict when an earthquake will occur, but it can be used to indicate likely locations. • Remote sensing (plate movements and electromagnetic disturbances). Allows sharing of GIS data with LIDCs. • Seismic Records...
Earthquakes represent the release of stress built up in the Earth’s crust due to tension, compression or shearing of rocks. A series of shockwaves originate from the earthquake focus and this point on the Earth’s surface is the epicentre. 95% energy released in first...
Ground shaking and Displacement: Locations close to epicentre, high magnitude and water content experience extreme ground shaking- Kobe, Japan 1995. Buildings withstand vertical movements better than horizontal. Surface displacement affects drainage, sewers, railways,...
People continue to live in tectonically active locations for a range of sociocultural, economic and environment reasons, such as: • Weathered lava produces fertile soils • Volcanoes provide opportunity for economic activity such as tourism • Tectonically active areas...
Different types of volcanoes: Super Volcanoes: Volcanoes that erupt over 1,000km3 of material in a single event. Yellowstone super-volcano in Wyoming, caldera 75km in diameter. Hot Spots: Basaltic Lava Constructive Margins Lower viscosity, hotter (1200 degrees) and...
Earth Structure: The lithosphere is the crust and the rigid upper section of the mantle (80-90km thick). It is divided into 7 large tectonic plates. The asthenosphere is a semi-molten layer in the mantle where rocks are easily deformed. Several 100s of kms thick, with...
Types of migration International Monetary Fund (IMF) defines globalisation as ‘the growing economic interdependence of countries worldwide through increasing volume and variety of crossborder transactions in goods and services, freer international capital flows, and...
Piracy: The act of boarding any vessel with intent to commit theft or any other crime, and with intent or capacity to use force in furtherance of this. Hot spots: Somalia, Indonesia and Nigeria Vulnerable route through Gulf of Aden and Red Sea, the Malacca and...
The importance of the oceans in the process of globalisation Globalisation = the growing integration and interdependence of people’s lives in a complex process with economic, social (cultural), political and environmental components. Time-space compression = a set of...
Many marine boundaries continue to be disputed, especially where there are known to be resources of energy, minerals or fish stocks. Tensions are likely to increase as populations continue to grow and become more affluent, increasing necessity for resources as current...
60 degrees North or South Formation of sea ice: 1. In the high latitudes more heat leaves the system than is inputted creating annual net deficit in heat budget. 2. Deficit occurs because the sun’s rays hit the surface at a low angle meaning less energy is spread over...
Monitored by Intergovernmental Panel on Climate Change (IPCC). Eustatic sea level change is increasing, currently 3.00mm per year. If all ice fields melted sea level would rise 70m. Causes • Thermal expansion of water Global warming increases surface temperatures and...
Ocean acidification 30% anthropogenic CO2 produced in the last 250 yrs has been absorbed in the ocean sink. Rising temperature reduces ability to absorb. Tipping point = the critical threshold which leads to irreversible change if passed Average global surface ocean...
Ocean circulation Marine debris from fluvial discharge, ship dumping and accidental discard. Global pollution: • ¾ UK beaches polluted with nurdles • Fishery equipment and ropes; breakdown forms microplastics • Most polluted place – Henderson Island, 17,000 tonnes...
Pollution Occurs when human activity adds a substance to the environment that affects organisms adversely and at a greater rate than at which it can be rendered harmless. Point source = release of pollutants from a single, clearly identifiable source Non-point source...
Oceans as ‘global commons’ Domains that lie outside the political reach of any one nation state (High seas, atmosphere, Antarctica, outer space). Tragedy of the Commons: An economic problem by Garret Hardin (American ecologist) – Exploitation overwhelms supply due to...
Oil and gas Non-renewable = resources that are finite on human timescales. “It makes no sense to talk about the sustainable use of a non-renewable resource (even with substantial effort + use rates). Any positive rate of exploitation will eventually lead to exhaustion...
The global distribution of the world’s oceans: The relief of ocean basins: Water deepens along continental shelf. Slope angle increases at continental slope. Wide, gently sloping continental rise. Flattest and deepest section abyssal plain which includes seamounts...
Horizontal and vertical changes in salinity and temperature: Salinity = A measure of the concentration of salt (NaCl). Measured as g per 1000g water (ppt) by NASA’s Aquarius Satellite. Freshwater - <0.5ppt Seawater – 35ppt Salinity is lowest in the surface zone and...
Factors affecting oceanic ecosystems: Net Primary Productivity (NPP) = the amount of carbon fixed by photosynthesis that exceeds respiration demands of the plant and goes into growth. Light Most intense over the equator. With increasing distance from the equator,...
An inter-tidal ecosystem: a salt marsh Salt marsh = coastal wetlands where ocean meets the land, common in mid-high latitudes. Form in sheltered estuaries where shallow water covers a low coastal gradient. Affected by incoming (flood) and outgoing (ebb) tides which...
Biological resources within oceans can be used in sustainable or unsustainable ways Ecosystem services The processes by which the environment produces resources used by humans such as oxygen, food, water + minerals. Supporting services: Necessary for production of all...