new horizons centrepiece The Fraser River Plume Martin Evans uses the example of a dramatic ocean phenomenon to show how all the elements of geography interact to shape the physical and human landscape

The water cycle and Human settlement GeographyReviewExtras the glacial history The flat oceanside land of the delta and the rich marine food resources have led to You can download a pdf of The Fraser River drains the interior of a long history of settlement by Canadian this spread to print as a poster at: British Columbia on Canada’s west coast www.hoddereducation.co.uk/ indigenous peoples. The first settlement with a catchment area over ten times the here was up to 9,000 years ago. This was geographyreviewextras 2 area of Wales (220,000 km ). In the spring an important trading area for aboriginal the melting of snow and glacial ice in the peoples and is now the site of Vancouver mountains of British Columbia sends a pulse (population 2.4 million) which is a major What is the Fraser of meltwater down the Fraser. port city, trading around US$200 billion in River Plume? The Fraser valley contains thick deposits goods annually. of glacial sediments deposited at the end If you take the Tsawwassen ferry from of the last ice age and mobilisation of some Vancouver to Vancouver Island during of this material in the spring flood produces the summer you may find yourself sailing high sediment concentrations in the river How geographical through a dramatic shift in the colour of water. Deposition of these sediments The Fraser Delta and the city the ocean surface. This is the boundary at the interface of the land and the sea of Vancouver. The Fraser systems interact between ocean water and the less saline, has created the Fraser Delta. Sediments River Plume is clearly visible The sediment flux from the Fraser River, more sediment-rich river waters from the which are not deposited in the distributary extending across the straits of Georgia between Vancouver conditioned by the past and present glacial mouth of the Fraser River. You are sailing channels of the delta enter the Strait of and Vancouver Island on history of the landscape, has a significant through the Fraser River Plume. Georgia to create the Fraser River Plume. Canada’s west coast impact on the coastal system, influencing coastal geomorphology, the marine ecosystem, carbon cycling and human Sailing through the The marine ecosystem Rich marine life in settlement. Understanding the processes Fraser River Plume the Strait of Georgia underpinning the great natural spectacle The fresh river water entering the strait of the Fraser River Plume reveals the has a lower density than the saline ocean, complexity of the interacting landscape and so the river water spreads out in a layer coastal systems which define the geography up to 10 metres deep across the surface of of this region. the ocean. The river water brings nutrients (particularly silica and iron) which promote growth of plankton and underpin the food webs which support rich biodiversity in the Further reading Strait of Georgia. This primary productivity dominates the More about the Fraser River Plume: organic carbon budget of the strait (50% www.oceannetworks.ca/fraser-river- of carbon inputs) together with dissolved plume and organic carbon inputs from the Fraser River (30%). Most of the particulate carbon is buried in ocean sediments and most Martin Evans is a professor of of the dissolved carbon (about 70% of geomorphology at The University of the total organic carbon) is oxidised to Manchester and an editor of carbon dioxide. Geography Review.

20 Geography Review February 2018 www.hoddereducation.co.uk/geographyreview 21