24 September 2012 Last updated at 11:41 ET

Skokholm island settlements uncovered by laser survey

New light has been shed on Skokholm's medieval history by aeriel mapping

Archaeologists say an innovative aerial laser survey has uncovered new clues to the history of a Pembrokeshire island.

Skokholm, best known for its colony of breeding seabirds, was known to have been settled in prehistoric times.

The Royal Commission on the Ancient and Historical Monuments of Wales says a new laser survey from the air shows detail of Iron Age and medieval use.

The research team involved now plans to visit the island to look for more evidence on the ground.

The survey technique - called LiDAR (light detection and ranging) - uses a laser mounted on a plane to draw a detailed model of the island's surface.

Dr Oliver Davis from the research team said is showed detail not visible on the ground or even from normal aerial photography.

"The laser scans can identify features that vegetation might hide, as little as a few centimetres high," he said.

"It's shown us unprecedented detail."

The new discoveries include the remains of enclosures and fields underlying the field pattern of the island's 19th Century farm.

Some of the discoveries show similar but less complex activity to that on the neighbouring island of Skomer.

The laser survey highlighted land features previously undetected (Images © Environment Agency and RCAHMW)

"There are at least three phases of occupation - we have known about prehistoric settlement because of scattered flints," said Dr Davis.

"But we can now see later Iron Age developments and also medieval earthworks near the 19th Century farm buildings.

"It's almost certainly a deserted medieval settlement, probably around the 15th Century.

"It's not as complex as Skomer - it might not have lasted as long, or was only seasonally occupied during the summer."

Dr Davis said the next step would be a visit to the island in 2013 to see if there was any evidence on the ground to add to the new discoveries from aerial scans.

Skokholm is owned by the Wildlife Trust of South and West Wales, which bought the majority of the island in 2007 and completed the purchase in May this year.

The island's lighthouse is currently being refurbished to provide accommodation for overnight visitors.

(Colour aerial photos of Skokholm © Crown: Royal Commission on the Ancient and Historical Monuments of Wales. LiDAR image © Environment Agency 2011 All Rights Reserved. Hillshade DSM view generated by RCAHMW)