Saltburn to Flamborough head Flashcards
What is the geology of the Flamborough coastline?
Adjacent North York Moores rise 400m above sea level - mainly comprised of sandstone, shales and limestone.
Southern end is a large chalk headland - topped with till - glacial deposit of the Devensian period.
Differences in rock resistance are responsible for the varied coastline scenery - notably the high cliffs and bays and headland sequence.
What is the wave energy like at Flamborough?
N-NW dominant waves - fetch of over 1500km - Saltburn is N facing so receives the highest inputs of wave energy.
Rates of erosion differ due to differing wave energy and geology - clay and shale experience erosion rates of 0.8m per year on average - sandstone as little as 0.1m.
wave height monitoring using buoys in Whitby Bay during 2010-11 - waves exceed 4m even in summer.
High energy input is also responsible for significant longshore drift - where headlands interrupt this beaches are formed - Filey bay
What are the main sediment cells and sources for the Flamborough coastline?
the coastline is sub-cell 1d of 1 which extends from St Abbs to Flamborough.
some of 1d has come from the nearshore area - driven onshore as the sea level rose after the last ice age.
sediment is also supplied through cliff erosion - sandstone and chalk boulders from cliffs and gravel from boulder clay deposits.
The river Esk is the only large river - enters the North sea at Whitby - supplies limited sediment due to the construction of Weirs.
How has the amount of sediment changed at Flamborough?
net increase of 9245m3 of beach sediment between 2008-2011 at Saltburn - Filey Bay had both accretion and beach erosion observed - reflect the influence of winter storms.
What are the cliffs like along the Flamborough coastline?
horizontally bedded sedimentary rock - causes cliff profiles to have a vertical face - most overlain by a layer of glacial till - cliffs made of chalk - very strong - 20-30m high - further N - steeper cliffs reflecting differing geology.
What are the shore platforms like along the Flamborough coastline?
High energy waves and active erosion means that the cliffs are retreating leaving behind rocky shore platforms.
Robin Hoods Bay - 500m width - extends much further into the off-shore zone - 1 - 15 degrees sloping - formed within the last 6000 years during a time of stable sea level.
What are the headlands and bays like along the Flamborough coastline?
The variation in rock type has led to a series of headlands forming as part of a discordant platform.
Robin Hoods Bay - weak shales eroded - resistant sandstone forms headland - Filey Bay has developed in weak clay surrounded by resistant limestone - most prominent headland at Flamborough formed of chalk - deep bays either side formed from clay.
What are the landforms like on headlands along the Flamborough coastline?
due to wave refraction - wave energy concentrated on resistant headlands that project into the north sea.
Fault lines and weaknesses are exploited by the erosive action of waves - enlarges them to form caves and arches.
Selwick’s Bay - master joint has been enlarged - Green Stacks Pinnacle - isolated at the end of the headland following the collapse of an arch roof.
Over 50 geos have formed along the coastline most aligned NE-NNE - dominant wave direction - where they meet faults blowholes have developed.
What are the beaches like on the Flamborough coastline?
They are few well developed beaches along the coastline - best are found in sheltered low energy environments such as Filey Bay.
Elsewhere sand and shingle accumulate slowly - owing to the low input of rivers and slow erosion of resistant rocks.
High energy waves also remove sediment before it can accumulate - high tidal range of 4m and lack of spits shows Longshore drift isn’t a big factor.
