Other formats

    Adobe Portable Document Format file (facsimile images)   TEI XML file   ePub eBook file  

Connect

    mail icontwitter iconBlogspot iconrss icon

Victoria University Antarctic Research Expedition Science and Logistics Reports 1996-97: VUWAE 41

Surveying of Beach Ridges:

Surveying of Beach Ridges:

Four benchmarks were put in for the event by the surveyors (K191) which were linked to sea level via the tide gauge at Cape Roberts. These were a combination of existing marks and two new ones at Dunlop Island (iron rod on top, by the large cairn), Spike Cape (on a large boulder near the isthmus connecting the mainland to the two tombolos), Kolich Point (on the 4th raised ridge at the point) and at Marble Point (WALO). This gave us a good starting point to run a GPS base station from, as well as a point to tie the levelling to for good height control. The GPS run was a Trimble Pro-xl and was used to give approximate locations for each surface exposure sample site, sites of each hole dug and other significant point.

Levelling was done using a dumpy level to reduce problems with battery power and reliability in cold weather which may have occurred using an EDM (electronic distance meter). This did mean a lot more time was spent on surveying than may have otherwise been needed but gave us height locations within 10 cm. A line was run out from the survey marks along the beaches to page break pre-selected locations where profiles were to be done. From pegs at each preselected location a profile was run from the water's edge (or shore attached ice) up to the marine limit. Each profile was closed to the pegs which were in turn closed back to the survey mark.

When these data are fully reduced there will be profiles of the beach ridges extending laterally over varying energy conditions along the coast. This should give an idea of the relationship between energy and height, as well as starting to give an idea of any differential uplift occurring on the coast. Where the marine limit was previously poorly constrained these surveys should give the height with more accuracy.