Describe the evidence that exists to show both positive and negative sea level change? (13)

There is much exhibit that exists to stir both collateral and shun ocean take change, geographical features such as rias, fjords, raise(a) beaches and other features of emergence both ar key render in exploring ocean aim change in past times. Ria is a Spanish word that means river mouth, and is used as a geographical term because of the many voices of rias on the brim of Galicia e.g. Ria de Pontevedra. They argon formed by the drowning of lower reaches of a river and its tri thoaries. This protuberance overred during the Holocene period, where many coastlines demonstrable ria systems. They draw to form mainly where the geological elan is at a right angle to the shoreline. In the British Isles we sight apprisevass some evidence of rias in Pembrokeshire, where alto break downher the rivers drain into Milford get downn. Rias give evidence for an general negative ocean level change, probably most potential to Isostatic reco genuinely, i.e. the retreat of app lesauce sheets taking pressure back make the degrade and the land therefore bouncing back, causing an boilers suit downslope in sea level. Fjords are similar to rias but rather than move into from drained V-Shaped river valleys they come from the more characteristically U-shaped glacial valley. They are mainly formed during the Holocene Transgression or Flandrian transgression where there was a rapid sea level rise. Fjords have swallow up sides and flat bottoms that contain very shallow water. Fjord coastlines tend to be best developed along high latitude coastlines where glaciation was most effective. For example the Norse coastline is the most fjord indented in the world, this coastline includes the 150km long Sognefjord. Fjords are likewise straightforward in the British Isles like in Scotland where Loch tangle and Loch Nevis are technically fjords although non as clear or as evident as in Greenland (independence Fjord) or Canada (Douglas Channel). Here we can obviou sly secure locations that have experienced ! rapid verifying sea level change mainly due to the Holocene Transgression, and as a emergence rias have formed. Raised beaches are non such an obvious expression of identifying negative sea level change but they are evidence nonetheless.

These are beaches that are embed high preceding(prenominal) the current beach level, sometimes on cliffs, or on any platform that cant be reached the tides. These beaches can be as high above the current sea level as 315m as is the case in Hudson Bay, Canada. In the British Isles the highest raised beach is on the Isle of theorize in Scotland where they been found at 37m above the curr ent sea level. These raised beaches all tend to be formed from Isostatic movements, where sea levels have dropped well very rapidly. As well as raised beaches, other features whitethorn occur as a expiry of coastal emergence. For example shore platforms can be raised up, and this is very evident in the tropics where platforms have formed high above the high tide mark. breastwork beaches may also occur when there is a spillage in sea level. Cliffs of the bevelled profile type may modernize as a result of relative rise in sea level. Here we see formations that provide evidence to suggest a sudden fall in sea levels perhaps due to Isostatic recovery. If you want to get a full essay, do it on our website: OrderCustomPaper.com

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