A team of geologists has started a project to digitise thousands of old maps and surveys, more than 150 years after the first geological survey of Ireland began.

The team from the Geological Survey of Ireland wants to scan its entire collection of maps and documents using powerful digital scanning technology.

Ultimately, the researchers hope to create a searchable database of the scanned material and make it available to the public on the internet.

The project has already begun and involves the digital scanning of about 1,600 field sheets, which make up the first geological survey of Ireland conducted between 1845 and 1887.

These maps contain information on the geological make-up of each county in Ireland, including detail on mineral deposits, fault lines and rock formations.

Some of the documents, which are extremely valuable, also contain architectural comment and sketching by the famous geologist and artist George Victor Du Noyer.

"These maps are a fantastically detailed resource,"' says Dr Matthew Parkes of the Geological Survey of Ireland.

"You can find out exactly where you are in an area from the field boundaries and rock locations on the maps.'"

The original maps were needed urgently earlier this year during the foot-and-mouth outbreak, when they were used to locate an appropriate site to bury animal carcases, according to Dr Parkes.

"The maps are consulted by mining and exploration companies and for all major civil engineering projects, including the Luas.

"The problem is they are getting worn out and damaged by overuse," he says.

Some of the originals have already been restored by experts at a high cost.

But the digitalisation project offers a much more cost-effective and user-friendly option in the long term, according to the survey team.

They are using a 40-inch wide 4040 colour scanner purchased from Dutch technology firm OcΘ. This has a scan resolution of up to 800 dots per inch and a scan speed of up to 1.3"/sec.

It scans the digital images of the maps and a computer program "vectorises" the data. This process enables the maps to be edited by using a computer program.

The scans are incredibly detailed at about 200 dots per inch and have enabled geologists using the new digital images to zoom in and uncover areas of the maps that were changed by their authors.

"Some of the geologists working during the 19th century changed their minds and rubbed out their findings," according to Mr Padraig Connaughton, chief superintendent at the Geological Survey of Ireland.

"These ghost images may be useful to historians or other geologists," he added.

A major benefit of the digitising of the images is that more people will be able to access the maps. Previously just one person could look at maps at a time, says Mr Connaughton.

Ultimately, the Geological Survey of Ireland wants to put all its documents on the World Wide Web but the quality of the scanned images mean the data storage space required for this operation would be huge, according to Mr Connaughton.

Each scanned map in the geological survey is 27 megabytes in size and the team estimate the size of the whole survey could be about 150 gigabits.

In the short term, a more economical way to give the public or companies access to the material would be burning CDs.

The first stage of the project to scan the field maps will take just a matter of months and £357,500 in funding has been made available from the Information Society Fund this year.

An application for further funding has been submitted to the Government to complete the full project. The survey team is hopeful that its digital survey will be completed well before the 42 years that it took to complete the original.