ADELAIDE: Matthew Flinders & the Coastal Landforms of SE Australia

Shortly after the Investigator sailed eastwards out of Spencer Gulf another gulf was encountered. While the new gulf was not as large, it was later to become important, as the future city of Adelaide (and capital of South Australia) was founded on the coastal plain on its eastern side. We know this smaller gulf Gulf St Vincent. Head of Gulf St Vincent - Link to SLSA's Flinders Journal - photo version Head of Gulf St Vincent - Link to SLSA's Flinders Journal - text version (Note: text version loads more quickly than photo version) Mt Lofty, prominent landmark: '... Mt Lofty Vis. 20 leagues ... Range of moderately high and well wooded hills whose elevation increases to the southward ... Low sandy shore, behind which the land rises gradually' - From Flinders' chart
Mt Lofty, SA This mountain lies directly behind Adelaide, the capital of South Australia. Mt Lofty is part of a long north-south mountain chain made up of sediments deposited many millions of years ago in a depression (or geosyncline). Later land movements within a broad shatter belt caused uplift of a block of hardened sediments that became the Mt Lofty Range. The highest point, Mt Lofty, has an elevation of 716m. The summit is well suited for telecommunication facilities and a lookout offers extensive views. The fault scarp on the Adelaide-facing (i.e. western) side of the range is a prominent feature; it has influenced Adelaide's easterly growth. Building on the steep upper slopes is expensive - it is necessary to protect homes against the danger of slippage. It is also difficult to maintain water supply. Flinders Column commemorates the discovery of Mt Lofty by Flinders in March 1802. The mountain can be seen from Kangaroo Island.	Flinders Column Mt Lofty, SA Photo1A. Flinders Column (left), Photo1B. Mt Lofty from Adelaide (right) Photo 2: Plaque at Flinders Column, Mt Lofty
Adelaide Plain Adelaide's CBD lies on a coastal plain, mid way between Gulf St Vincent (in the distance) and Mt Lofty. The plain becomes narrow towards the south (left of photo), and hence Adelaide's urban mass also becomes narrower in this direction. In the north the plain widens; there is considerable room for expansion in this direction, but the outer suburbs are already some considerable distance from the CBD. The Mt Lofty Range, like the Flinders Ranges to the north, rises abruptly from the surrounding lower areas, generally along fault planes. These steep slopes serve as parklands for the city's inhabitants and habitat for native plants and animals. It also acts as a barrier to the city's eastern expansion.	Photo 3: Adelaide CBD & suburbs (from Mt Lofty)
Adelaide's coastline Sand is moved by currents along beaches. This process is called longshore drift, and along the Adelaide beachfront it operates in a northerly direction . The breakwater shown is believed to disrupt this flow, depleting sand supply on its northern side. Beach reconstruction work and other coastline projects taking place in the area appear to be aimed at reducing problems of sand supply and instability.	Photo 4: Adelaide coastline, towards Glenelg (Dec 2001)
Vegetation at the location shown (i.e. West Beach - see photos above and below) is being re-established, and is protected by fencing. Coastal vegetation improves the appearance of an area, offers habitat for native plants and animals, and reduces wind-induced sand movements and inland penetration of salt-laden winds. Unfortunately the protective fencing does not enhance the area's appearance. Sometimes after successfully restoring vegetation it may be possible to remove fencing. The suburb of Glenelg shown in the middle distance (above), is Adelaide's most important suburban tourist locality. The photo illustrates the nature of the coastal plain south of Adelaide. Going south the plain becomes narrower, becoming hemmed in by the rugged coastal hills of the Fleurieu Peninsula.
The Adelaide coastline has been almost fully developed and therefore considerably altered since settlement began. At present the beach is undergoing further (intentional) modification with the aims being to (a) replenish sand where necessary, and (b) to restore vegetation to as natural a condition as possible. To help understand the natural processes of, and to evaluate the human impacts upon, the beach system, an ongoing research and monitoring project is being carried out by the SA Coast Protection Board. This occurs at numerous sites (including West Beach) along the Adelaide coast (from Kingston Park in the South to Outer Harbour in the north).	Photo 5 - West Beach, looking north
Offshore vegetation While a wide beach is a helpful way to reduce wave energy (and hence erosion) along the coastline, and while vegetation reduces wind strength (and hence sand loss through wind erosion), it is not as often that we consider what is happening below sea level. Beneath the sea, sand extends offshore; if vegetated, it is stable (as also is sand above the water level). However, offshore sand can be moved by waves and currents if the vegetation is removed. Loss of vegetation, sea grass in this case, through declining water quality, is taking place off the Adelaide beaches; evidence shows that large amounts of sand are presently mobile. A key reason for the present monitoring programme extending offshore is to improve understanding of the rate of sand movements below, as well as above, sea level.
Glenelg In keeping with enjoyment of beach areas in many parts of Australia by tourists and residents, resort facilities are well developed, as are specialist shopping and eating facilities. Glenelg is connected to Adelaide's CBD by tram. Recent studies have also shown that Australians in general are interested in coastal lifestyles, and there is a noticeable nation-wide movement of people to seaside locatons.	Glenelg Photo 6: Glenelg, looking along the famous pier Photo 7: 1836 Settlers ship monument, Glenelg This is a square-rigged, three masted sailing ship, not unlike the Investigator
'In honour of the noble admiral who presided at the Board of Admiralty when I sailed from England ... I named this new inlet, the Gulf of St Vincent. To the peninsula which separates it from Spencer's Gulf, I have affixed the name of Yorke's Peninsula, in honour of the Right Honourable Charles Philip Yorke ...' - Matthew Flinders in Terra Australia [March 1802]	Gulf St Vincent (Adelaide) chart Extract from Flinders' chart, Gulf of St Vincent - Mt Lofty (including present-day Adelaide)
Study the chart (right). It shows the Investigator's track, as well as the key features of Spencer Gulf (left), Yorke Peninsula (centre), Gulf St Vincent (right) In summary: 'Our examinaton of the Gulf of St Vincent was now finished; and the country round it had appeared to be generally superior to that on the borders of Spencer's Gulf. Yorke's Peninsula between them, is singular in its form, bearing some resemblance to a very ill-shaped leg and foot ... ' - Matthew Flinders in Terra Australia [April 1802]	Extract from Flinders' chart - Gulf St Vincent