The Twelve Apostles, in Australia, are a series of limestone stacks off the Great Ocean road that connects the cities of Melbourne and Portland. Strong winds and storms are eroding one of the coast's most visited environmental attractions at impressive speed.
The genesis of the Twelve Apostles began between 10 and 20 million years ago, when they were still part of the rocky coast. The detachment took place due to the slow erosion brought about by adverse conditions and the waves of the Southern Ocean.
At first caves were formed, then arches that gave life to these stacks almost fifty meters high. Over the years, several Apostles have succumbed to the forces of the winds of erosion: the latter continues to carve the bases of the stacks with a speed of two centimeters a year.
Until 3 July 2005, there were nine stacks, but suddenly a monolith collapsed into the ocean waters in less than a minute. In 2002, the Port Campbell Professional Fishermens Association attempted to block the creation of the Twelve Apostles Marine National Park at the Twelve Apostles site.
The association approved of a later decision by the Victorian government to prohibit seismic exploration at the site by Benaris Energy, believing such exploration would harm marine life. Today the Apostles are eight, even if several rock formations can be seen under the water surface.
Although the number of monoliths is always changing, the nickname of The Twelve Apostles has been adopted for purely tourist purposes. Until 1922 they were called the Sow and Piglets, meaning the sow and piglets.
The Twelve Apostles were formed by erosion.
The harsh and extreme weather conditions from the Southern Ocean gradually erode the soft limestone to form caves in the cliffs, which then become arches that eventually collapse, leaving rock stacks up to 50 m high. The stacks are susceptible to further erosion from waves.
In July 2005, a 50-meter-tall stack collapsed, leaving seven standing at the Twelve Apostles viewpoint. Due to wave action eroding the cliffs, existing headlands are expected to become new limestone stacks in the future.