Sun. Feb 5th, 2023
Five British coastal wonders to see before heading down the road from Malta's Azure Window

Ginger Inc.

When Malta’s world-famous Azure Window collapsed into the sea in severe storms earlier this year, the loss of one of the world’s natural wonders provoked strong emotional reactions. From stunning photographic tributes on social media to the ever-ruling memes, countries banded together to commemorate this iconic stretch of Gozo’s coastline.

While Maltese Prime Minister Joseph Muscat tweeted that it “heartbreaking“, he rightly affirmed that it was inevitable. Humans walking across the arc may have accelerated the collapse, but its downfall was unfortunately inevitable as global sea levels rose.

The transient nature of cliffs and beaches is evident in the loss of many beautiful features over the decades. Arch Rock in Freshwater Bay, on the UK’s Isle of Wight, formed by centuries of coastal erosion, collapsed in 1992, while a huge chunk of cliff near Lulworth in Dorset, UK, disappeared without warning in April 2013. of the South West Coast Path saw tens of thousands of tonnes of lime disappear into the sea overnight.

Even more recently, a sandy beach returned to Dooagh on Achill Island off the west coast of Ireland just as suddenly as it had 33 years earlier.

As Britain’s coastline evolves in response to sea level changes, there are many spectacular features that are at risk from sea erosion. The changes in coastal geomorphology are also likely to be faster and more profound as sea levels rise and storms intensify due to global warming. Consequently, it is difficult for geologists or geomorphologists to predict when a major change will occur, so it might be wise to visit some of our coast’s wonders now before they disappear forever. Here are my top five must-see UK sites from the most endangered list.

Orkney's Old Man of Hoy was still part of the headland in 1750.

Orkney’s Old Man of Hoy was still part of the headland in 1750.

Shutterstock

1. Old Man of Hoy (Devonian sandstone), Orkney

Orkney’s legendary Old Man of Hoy is Britain’s highest sea stack, standing at an imposing height of 137 meters above sea level. In geological terms it is relatively young and maps indicate that it was still part of the headland in 1750. Yet this sandstone column coveted by climbers and wildlife began its evolution more than 400 million years ago on the edge of Lake Orcadie, a vast freshwater area. lake that covered the area from the south coast of the Moray Firth to Shetland in the north.

Dark basaltic lava from the lake bed now forms the foundation of the structure, with horizontal beds of red and yellow sandstone creating the tiered overhanging profile for which it is famous. So how soon should we visit this iconic structure?

With a 40m vertical crack in the top of the south face and daily storms from the sea on the narrow 30m base, The Old Man of Hoy faces constant erosion from gale force winds and high energy waves. Over 100 years ago, the pile looked very different with an arch at the bottom of a much wider base, hence the name. Evidence of the arch’s collapse is visible in the large rocks scattered along the shoreline.

Bow Fiddle Rock may be about 541 million years old.

Bow Fiddle Rock may be about 541 million years old.

Shutterstock

2. Bow Fiddle Rock (Neoproterozoic Quartzite), Portknockie

Bow Fiddle Rock is a natural sea arch near Portknockie on the north east coast (Moray Firth) of Scotland, resembling the tip of a bow fiddle. It is composed of resistant quartzite sandstone – hard, non-foliated metamorphic rock, which was originally pure quartz sandstone – from the Neoproterozoic Era (1000-541 million years ago). It forms the coastal cliff backdrop between Cullen and Buckie and is exposed to the erosional forces of the North Sea.

Durdle Door on Dorset's Jurassic Coast is the result of coastal erosion weakening fractures in the limestone cliffs.

Durdle Door on Dorset’s Jurassic Coast is the result of coastal erosion weakening fractures in the limestone cliffs.

Shutterstock

3. Durdle Door (limestone from Portland and Purbeck), Dorset

South Dorset’s Jurassic Coast, a UNESCO World Heritage Site, beautifully showcases the progressive and damaging effects of sea level rise. Durdle Door is a naturally formed arch resulting from coastal erosion that takes advantage of fractures in the Portland and Purbeck limestone. Just a few miles to the east, the spectacular crescent-shaped Lulworth Bay shows what happens when the resistant limestone is removed to expose the softer Cretaceous (Wealden) sediments to the full onslaught of the English Channel.

Chesil Beach is 29 km long, 200 meters wide and in places up to 15 meters high.

Chesil Beach is 29 km long, 200 meters wide and in places up to 15 meters high.

Shutterstock

4. Chesil Beach (post-glacial pebble beach), Dorset

Chesil Beach is also part of the Jurassic Coast and is one of only five major natural shingle beaches in Britain. This spectacular feature is 29 km long, 200 meters wide and 15 meters high in places. The shingle, consisting of flint, granite, chert, quartzite, porphyry and tourmaline rock ranges from the size of a pea in the northwest to the size of an orange in the southeast. According to legend, smugglers who landed on the beach could tell their location from the size of the pebbles under their feet.

Often described as a tombolo (or headland) connecting an island to the mainland, Chesil Beach evolved as a barrier beach that originated in the English Channel at the time of the last great ice age when sea levels were 125 meters lower than today. It then migrated east as sea levels rose in response to ice melt, before finally joining the mainland with the island of Portland. A further rise could mean breaching the beach, restoring sea connectivity and making Portland an island again.

The Pembrokeshire coastline here has been chemically eroded over the centuries as the limestone has dissolved

The Pembrokeshire coastline here has been chemically eroded over the centuries as the limestone has dissolved

Shutterstock

5. The Green Bridge of Wales (Carboniferous Limestone), Pembrokeshire

Regularly gracing the pages of travel guides and textbooks, the Green Bridge of Wales is a wonderful example of our developing coastline. Composed of a thick Carboniferous limestone, including some chert – a dark, hard and opaque rock made of silica – the shoreline has been chemically eroded over the centuries as the limestone has dissolved. Pebbles have been thrown against the rocks, gale-force winds have weakened the structure and sand particles have scoured the surface.

The Green Bridge of Wales has eroded on both sides of the small headland, resulting in the formation of caves that eventually came together to create the arch visible today. The constant tension the arch undergoes means that, like the Azure Window, it will one day fall. A visit is highly recommended before it becomes a pile.

Sea level rise

If sea levels rise by a third of a metre, the coastline in low-lying areas could be pushed back by 610 metres, which would have a huge effect on the world’s beaches in general. The increased rate of sea level rise could also reduce the uplift effects that North Britain is experiencing as a result post-glacial rebound -tThe rise of land masses once pressed by the sheer weight of ice sheets from the last ice age – even threatening Scotland’s world-famous links golf courses.

As sea levels are expected to rise significantly over the next century, other wonders of Britain’s natural environment could be endangered, including the Giant’s Causeway in Northern Ireland and its Scottish counterpart, Fingal’s Cave in the Inner Hebrides.

Sculpted by erosion, some of these extraordinary formations may be gone in years to come, but they show that what we love and revere today is very different from a century ago.

The conversationWhile we may mourn the loss of beloved geological features to our coastlines, the evolution of each natural treasure and the creation of new ones holds the promise of bringing new wonders for future generations to appreciate.

John Richard Underhill is a senior scientist and professor of exploration geosciences at Heriot-Watt University.

This article was originally published on The Conversation.

Frame image by Ginger Inc.

By akfire1

Leave a Reply

Your email address will not be published.