Coastal erosion around Bridlington, southside of Flamborough (by N.Yamaguchi)

Bridlington, southside of Flamborough (East Riding of Yorkshire) by N.Yamaguchi

Keywords: Beach, Coastal erosion, Chalk bed, Till
*See Framborough about the chalk bed and the Quarternary sediments here !

I visited southside of Flamborough Head (Fig. 1). I started to walk along the shoreline from Bridlington.

Fig. 1 Aerial photo of UK and Flamborough Head by Google Map.

It was impressive that there were shore protection and groynes along the shoreline of Bridlington (Fig. 2). When I returned to Hull, I investigated some previous studies about coastal erosion around east Yorkshire, and I learned that Bridlington area has been forced to take measures against coastal erosion for a long time. An old book Matthews (1913) reported that the coastal cliff, which consists of till, had been estimated approximately 1.8 m/year around Bridlington before the shore protection. I knew that Byobugaura, which is a famous coastal cliff in Japan (sometimes called ‘Oriental Dover’ :D), had retreated ~1 m/year before shore protection. So, I was surprised at the high rate of the shoreline retreat around Bridlington.

Fig. 2 Coastal area of Bridlington.

When I walked north from Bridlington and came near Sewerby, surface feature of the coastal cliff changed from talus slope to precipitous shape (Fig. 3).

Fig. 3 Shoreline from Bridlington to Sewerby.

This difference of the surface feature reflects geology: crumpy till and tougher chalk, respectively. A previous study estimated the retreat rate of the chalk cliff around Sewerby as ~0.3 m/year. This obvious contrast of coastal erosion between till and chalk cliff is interesting.

There are a lot of round chalk cobbles at the base of the cliff around Sewerby. They are also rare in Japanese coast.

Fig. 4 Chalk cliff and round cobbles at Sewerby.

I climbed the stairs at Sewerby and walked to Bridlington. I was surprised that everyone can walk near the edge of the cliff there (Fig. 5). In Japan, top of coastal cliffs like there is generally prohibited to approach. However, around Sewerby, we can walk along paths near the edge. Additionally, there are good benches! That scene was intriguing for me because I felt a slight difference in the way of thinking about natural risks and responsibility between Japan and UK.

Fig. 5 Top of the cliff around Sewerby.

Meeting at Heriot-Watt Univ. (by N. Nishida)

13 March 2019: Meeting at Heriot-Watt University (by N. Nishida)

I (Nishida) and a PhD student of University of Hull had a meeting with researches of Institute of Petroleum Engineering. The main topics were several projects of deep-sea sediments including contourite and sediment-gravity-flow-deposits. We shared our own research and discussed about the results. We also discussed about sampling strategy from IODP legacy core for a new project. I will complete the sample list and will request approval from IODP.

Main gate of Heriot-Watt University (13 Mar 2019)

Meeting at Royal Holloway, Univ. of London (by N. Nishida)

4 March 2019: Meeting at Royal Holloway, University of London (by N. Nishida)

I (Nishida) had a meeting with researches of Department of Earth Sciences. The main topics were several projects of the contourite, one of the representatives of the deep-sea sediments. We discussed about the interpretation of our own data and strategy of further analyses for an ongoing project. Also, we clarified focus and methods for a new project. They will send me samples for the project.

 Building of the Department of the Earth Science, Royall Holloway, University of London (4 Mar 2019)

Framborough (chalk bed, glacial deposit, coastal erosion)

Framborough (East Riding of Yorkshire)  7 July, 2018

Keywords: Beach, Chalk bed, Till, Quaternary
*See Bridlington about the coastal erosion here !

I visited Framborough to observe chalk bed, till and coastal erosion.

Fig. 1. Locality of Framborough.

Framborough is located on the headland in the eastern coast of Britain Island (Fig. 1).

The headland consists of the Cretaceous chalk beds (Fig. 2). We can observe the beds in the coastal cliff.

Fig. 2. Chalk bed with white color in Framborough.

We can observe till deposited Quarternary over the chalk beds (Fig. 3). This is my first time to observe till and glacial deposits which is difficult to find in Japan because glacial didn't develop in Japan during glacial stages in Quarternary.

Fig. 3. Till over the chalk bed.

The till consists of gravel, sand and silt without structures (Fig. 4). The base, contact with chalk beds, are erosional surfaces which are undulated (Fig. 5).

Fig. 4. Close-up of till.

Fig. 5. Contact between chalk bed and till.

In Japanese case, fluvial or shallow marine deposits with tephra are distributed on surfaces of many coastal areas. From the sedimentary environment and the depositional ages using tephra and the altitude, we can reconstruct tectonic, paleo sea-level and geological histories of the area. The activities of some active faults in Japan which can occur earthquakes in near future are estimated based on this method. I am also using it in Japan but I feel that it is difficult to apply the method to the Quarternary which consists of glacial deposits in UK because the method requires the altitude of paleo plain-surfaces or deposits which were formed under strong influence by sea level, for example beach or tidal flat, as indicators of paleo sea-level. The difference of the altitudes of basal erosional surfaces, by river or wave, of other glacial stages is also useful to reconstruct tectonic history but erosional surfaces of glacial seems to be independent from sea level.

In addition to this, we have to consider about post-glacial rebound occurred in UK (Western Europe and North America, birthplace of and pivotal areas for geology) to reconstruct the tectonics.

Withernsea (offshore wind power, coastal erosion)

Withernsea (East Riding of Yorkshire)  1 Sep., 2018

Keywords: Offshore wind power, Coastal erosion

I visited Withernsea to see offshore wind turbines and to observed coastal erosion (Fig. 1).

Fig. 1. Locality of Withernsea.

Many wind turbines were lined up off the coast of Withernsea (Fig. 2). I could see at least hundred turbines with sevral hundred of meters interval.

Fig. 2. Many wind turbines off Withernsea.

It seems to be difficult to fishing in the area. In Japan, inshore fishery is active in many coastal areas so coexistence with fishery will be one of the subjects for Japanese offshore wind industry, I think.

The coast of Withernsea is protected from coastal erosion by levee and large stones (Fig. 3).

Fig. 3. Northern coast of Withernsea.

On the other hand in coast around the town, there are no levee and severe coastal erosion is in progress (Fig. 4). Some houses and roads were lost due to the erosion (Fig. 5).

Fig. 4. Southern coast of Withernsea.

Fig. 5. Satellite image of the southern coast of Withernsea.

The coastal cliff is consisted of till and we can find many landslide surfaces (Fig. 6). But there are no landslide deposits or talus in the bottom of the cliff. They will probably be eroded easily by wave during high tide when the beach in front of the cliff is submerged. In Japan with micro-tide, most of beach is not submerged entirely even during high tide. I think I need to pay more attention to tidal range when I discuss about coastal erosion.

Fig. 6. Till outcrops the coastal cliff.

Birmingham and Nottingham (redeveloped canal, fluvial deposit)

Birmingham and Nottingham (Midland) 29 Oct. to 30 Oct., 2018

Keywords: Canal, Redevelopment, Fluvial deposit

I visited Birmingham and Nottingham in Midlands on the way home from Cardiff and saw the canals and sandstone there (Fig. 1).

Fig. 1. Localities of Birmingham and Nottingham

Birmingham is the second-most populous city in the United Kingdom and important city of traffic because of the canal and train, especially after Industrial Revolution. I couldn't found the interesting things in geology during my two hours visit but found the canal redeveloped to stylish shopping area from coal transport ways (Fig. 2) like Cardiff Bay. It will be important to prevent mud deposition if canal is used for transport. Geologist can tackle the subject. But now, how can geologist contribute to such a redeveloped canal ?

Fig. 2. The canal redeveloped to stylish shopping area in Gas street basin. Cafes and pubs are located along the canal. Some small cargo ships are in business as pubs on the canal.

Nottingham is famous for the legend of Robin Hood. I visited there to observe Castle Rock which is type section of Early Triassic Nottingham Castle Sandstone Formation (Figs. 3 and 4). The sediment is located base of Nottingham Castle and fluvial deposit which is consist of sand and gravel with cross bedding.

Fig. 3. Nottingham Castle Sandstone Formation at the base of Nottingham Castle.

Fig. 4. Nottingham Castle Sandstone Formation. Beautiful cross bed is developed.

Cardiff Bay (tidal flat, huge port with water gate)

Cardiff Bay (Wales)  27 Oct., 2018
Keyword: Estuary, Port redevelopment, Water gate

I visited Cardiff to observe Cardiff Bay faces to Bristol Channel. I was expecting to observe a natural macro-tidal estuary with beautiful sedimentary structures and bedforms. But I could see artificial huge dam lake there.

Cardiff is capital of Wales and located in front of Cardiff Bay which faces to Bristol Channel and has developed as a port to export coals after Industrial Revolution (Fig. 1).

Fig. 1. Locality of Cardiff Bay.

I visited the city but there were few things to see from a view point of sedimentology. So I moved to Penarth, south of Cardiff Bay, to observe beach faces to Bristol Channel with about 8 m in tidal range. Mainly gravel are distributed in the beach (Fig. 2) and mud and sand were partially distributed (Fig. 3). Ripple was developed only on sand and muddy areas were slightly higher than other areas (Fig. 4). It is very interesting how these sediment with various grain size transported and distributed like this.

Fig. 2. Beach of Bristol Channel in Penarth, south of Cardiff.

Fig. 3. Gravel and mud were distributed.

Fig. 4. Ripple was developed only on sandy areas and muddy areas were higher.

Sedimentary rock was outcropped at the cliff in back of the beach (Fig. 5).

Fig. 5. Sedimentary rock in Penarth, south of Cardiff.

The cliff is very dangerous because I saw the rocks with human-head size fallen from the cliff many times during my only two hours visit and probably supplies many gravels to the beach. The sediment seems to have wave ripple and shell beds but I couldn't observe the sediment in detail because of fallen rocks.

After the observation of the beach, I walked to Cardiff Bay along the beach and was surprised. There were huge levee (Fig. 6) and I saw beautiful clear blue water inside the gate(Fig. 7). Cardiff Bay is completely separated from Bristol Channel by huge levee (Fig. 8).

Fig. 6. Levee in Cardiff bay. Three people on the levee.

Fig. 7. Inside (lower left) and outside (lower right) views of the levee in Cardiff Bay

Fig. 8. Satellite image of Cardiff Bay.

There are marina and people enjoy marine sports inside the levee. People also enjoy running and cycling on the levee, shopping and dinner in shopping mall and pub around the "bay". The "bay" was redeveloped to a stylish water front resort from a port for coal export after 1980's.

To observe tidal flat is as enjoyable as marine sports and shopping, I think (maybe many people don't agree with) .