Spectacular Coastline
This image looks at The Twelve Apostles, a collection of limestone stacks running along the coastline in Port Campbell National Park, by the Great Ocean Road in Victoria, Australia. Their proximity to one another has made the site a popular tourist attraction.
Originally the site was called the Sow and Piglets. Muttonbird Island near Loch Ard Gorge was the ‘Sow’ and the smaller rock stacks the 'Piglets'. The name was changed in the 1950s to present the name recalling the biblical The Twelve Apostles.
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in their formation which starts when part of a headland is eroded by hydraulic action (the force of the sea crashing against the rock). That force weakens cracks in the headland, causing them to later collapse, forming free-standing stacks and even a small island. Without the constant presence of water, stacks also form when a natural arch collapses under gravity, due to sub-aerial processes like wind erosion.
Stacks can provide important nesting locations for seabirds, and many are popular for rock climbing. They typically form in horizontally bedded sedimentary or volcanic rocks, particularly on limestone cliffs.
An updated version of something I posted a long time ago.
Spectacular Coastline
This image looks at The Twelve Apostles, a collection of limestone stacks running along the coastline in Port Campbell National Park, by the Great Ocean Road in Victoria, Australia. Their proximity to one another has made the site a popular tourist attraction.
Originally the site was called the Sow and Piglets. Muttonbird Island near Loch Ard Gorge was the ‘Sow’ and the smaller rock stacks the 'Piglets'. The name was changed in the 1950s to present the name recalling the biblical The Twelve Apostles.
A stack is a geological landform consisting of a steep and often vertical column or columns of rock in the sea near a coast, isolated by erosion. Stacks are formed through processes of coastal geomorphology, which are entirely natural. Time, wind and water are the only factors involved in their formation which starts when part of a headland is eroded by hydraulic action (the force of the sea crashing against the rock). That force weakens cracks in the headland, causing them to later collapse, forming free-standing stacks and even a small island. Without the constant presence of water, stacks also form when a natural arch collapses under gravity, due to sub-aerial processes like wind erosion.
Stacks can provide important nesting locations for seabirds, and many are popular for rock climbing. They typically form in horizontally bedded sedimentary or volcanic rocks, particularly on limestone cliffs.
An updated version of something I posted a long time ago.