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...
Exploring Oceans
Oceans present hazardous obstacles to human activities
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...
How have socio-economic and political factors influenced the use of the oceans?
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...
Oceans are important spaces where countries challenge each other
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...
Climate change is altering high latitude oceans
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...
Climate change is altering sea levels
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...
Climate change and the ocean system
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 currents disperse / concentrate pollution
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...
There are a variety of pollutants that affect the ocean system
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...
Governing the oceans poses issues for the management of resources
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...
The use of ocean energy and mineral resources is a contested issue
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 world’s oceans are a distinctive feature of the Earth
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...
Water in the world’s oceans varies
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...
The biodiversity of oceans
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,...
What are the opportunities and threats arising from the use of ocean resources?
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...