evidence for isostatic and eustatic sea level changes
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EVIDENCE FOR ISOSTATIC AND EUSTATIC SEA LEVEL CHANGES. What does isostatic mean? What does eustatic mean? Which is changing in these photos – land level or sea level?. Aerial view of the raised beach on the west coast of Arran. - PowerPoint PPT PresentationTRANSCRIPT
EVIDENCE FOR ISOSTATIC AND EUSTATIC SEA LEVEL CHANGES
•What does isostatic mean?•What does eustatic mean?•Which is changing in these photos – land level or sea level?
Aerial view of the raised beach on the west coast of Arran.
Old stacks
Raised beach covered with coarse shingle.
Old cliff line
Diagram from Arrran and the Clyde Islands, Scottish Natural Heritage
Raised beaches
http://www.bbc.co.uk/scotland/education/geog/coastline/standard/physical/features/sea_level/
Sea level 13,000 years ago
Sea level 6,000 years ago
Sea
Cross section though raised beaches
RockCave
Rock platform
Beach
Raised beaches
Stack
King’s CaveAll the caves are full of very rounded pebbles , which have the same texture as beach pebbles.
The caves also contain many marine shells, which are encrusted with lichens. They are not part of the present marine deposits.
Raised sea stack, Bute.
Raised beach
Diagram from Arrran and the Clyde Islands, Scottish Natural Heritage
Raised beach deposits are
usually made of coarse, rounded pebbles. This
deposit is cemented with iron. Godrevy Point, Cornwall
River terracesThe Graded Steam
Idealised cross section
Upper reaches
Middle reaches
Lower reaches
Oblique view upstream
Terraces
Knick point
A
B
C
A
C
B
Idealised long profile
Knick points
Sea level 2
Sea level 3
Sea level 1
River