Showing posts with label Pumice. Show all posts
Showing posts with label Pumice. Show all posts

Sunday 9 March 2014

Huge deposits of pumice on the beaches

Piles of pebbles of pumice lie on the tide-line along the new South wales south coast
The sandy beaches and hidden coves of the New South Wales south coast are presently littered with pumice pebbles. They have come from 4000 km out in the Pacific Ocean, north of New Zealand, where a submarine volcano on the Havre Seamount, near the Kermadec Islands erupted last July. This caused a raft of pumice covering 20,000 sq km to form and gradually drift west on the currents. When they reached the Australian coast they were washed up and concentrated on the tide-line. 

The pumice formed as lava erupted under water and air trapped in tiny pockets in the rock makes the it buoyant. This was the largest such eruption in the region for over fifty years. There were all sorts of plant and animal life attached to some of the larger and rougher pieces, and I wonder what land-based life will find a niche in the new rocky tide-line. 

The pumice is light and floats like the bladders of the seaweeds which it lies with on the shore

Most of the pebbles are small, but some are as large or larger than a cricket ball

The pumice floated from north of new Zealand to the south east coast of Australia