Pictorial supplement to glossary
[ This page is a work in progress. Last attention 15 April 2021. ]
BACKWASH. The return, under gravity, of water to the sea after waves break on a beach. A new wave rolls in at an angle to the beach as water from the previous wave (foreground) drains directly back into the sea. Associated action is swash [Ulrome: 10 June 2012].
BUTTRESS. A natural cliff feature having a protruding angular aspect that makes it look like a support. May be formed when a slide-smoothed section has itself slipped [Ringbrough south: 6 May 2013].
CAVE. This example has an arch of clay at the entrance [Ringbrough south: 6 May 2013].
COLLAPSED CAVITY (1). The roof has fallen in. On both sides, till has overslumped a unit of coarse sand and gravel that runs across the cavity [Atwick: 26 May 2013].
COLLAPSED CAVITY (2). Groundwater trickling from above may have contributed to the failure [Dimlington: 14 March 2014].
FALL CAVITY (1). Generally on a bigger scale than a collapsed cavity, with material separating from the back and sides as well as from above. At the lower left of the cliff face, vertical rilling and a wave-smoothed undercut are apparent [Hilston: 7 May 2013].
FALL CAVITY (2). Mudballs
are forming from the material on the beach [Grimston: 7 May 2013].
SLUMP CAVITY (1). Often the result of a waterlogged cliff after prolonged rain. Clay turns to mud which oozes to the beach, leaving a cavity or – as here – multiple cavities [Ringbrough south: 6 May 2013].
SLUMP CAVITY (2). This slump cavity at the upper cliff is dried out [Atwick: 26 May 2013].
SHALLOW CAVITY. Cavity of little or moderate depth [Ringbrough south: 6 May 2013].
FINGER (1). A vertical piece mainly separated from the cliff but still connected at its base [Holmpton: 20 April 2013].
FINGER (2). Here supported on a plinth [Hollym: 17 August 2013].
IMBRASION. To the right of the cave, material has been plucked from the cliff face leaving an imbraded shallow cavity [Ringbrough south: 6 May 2013].
JUT (1). Small seaward projection of the cliff line. The picture shows a ‘V’ jut [Hilston: 6 May 2013].
JUT (2). The forward part of this jut appears twisted. A small erratic is lodged at the base of the overhang
[Grimston: 7 May 2013].
JUT (3). Rectangular jut, partially overhanging [Atwick: 26 May 2013].
MILLING. The stones clustered at the foot of the cliff will, when pushed around by waves, grind away at the clay on each high tide that reaches the cliff [Grimston: 7 May 2013].
OVERSLUMP (1). Withernsea Till (‘chocolate’ coloured), having slid, covers the lower Skipsea Till. This is a commonly seen feature in southern sections of the coast. See till types
[Grimston: 7 May 2013].
BLOCKY OVERSLUMP. Again, Withernsea Till slides over Skipsea Till [Dimlington: 3 September 2012].
PLATFORM STEP. Formed in the clay platform, itself an indicator of active erosion, when the beach level is dropping. In this example, the step has a covering of shingle and stones [Dimlington: 3 April 2013].
SAND STEP. Similarly to a platform step, a sand step is the result of a reduction in beach level [Dimlington: 3 April 2013].
RUNNEL. As a sand bar (left) ‘pulls’ seaward from the upper beach (right) a channel, or runnel, is created. For more information, see the sediment segmentation
page [Grimston: 7 May 2013].
SEEPAGE LINE. Groundwater emerges from the filled-in bed of an extensive glacial outwash channel at middle cliff. During retreat of the ice, the flow of meltwater would have been landward, away from the camera [Ringbrough south: 6 May 2013].
SLIDES AND SLUMPS. At the upper cliff is an incipient slide – the sections are slipping in more or less one movement. In the lower part, material is slumping and falling. Also in the picture, at the foot of the cliff to the right, is an instance of imbrasion
. On the beach, a runnel
crosses the picture [Grimston: 7 May 2013].
SLIDE. Pastures Lane, once a link between the villages of Tunstall and Hilston, also served fields between it and the sea. Section by section, the old route drops and breaks away [Hilston: 6 May 2013].
RAZOR SPUR. Sometimes noted as a saw-tooth spur [Atwick: 26 May 2013].
SNOUT. Fine example at the foot of a razor spur [Ringbrough south: 6 May 2013].
STRAND LINE. Recent tides have not reached the base of the cliff [Hilston: 7 May 2013].
STRINGER. This stringer of chalk, crushed and spread by glacial action, lies below a bed of red clay [Atwick: 26 May 2013].
TOE HORN. A second example can also be seen [Atwick: 26 May 2013].
TOE BOULDER. Mud boulder attached to a cliff toe [6 May 2013].
WATER CUT. On reaching the edge of the cliff, an open drain or dyke will normally create a deep indentation such as this [Atwick: 26 May 2013].
more on East Yorkshire coastal erosion
Pictures and text by Brian Williams.