What happened to the lost colony of Roanoke Island? Remote sensing unearths clues to 400-year-old American mystery



A satellite survey of island has helped identify key areas of interest



Scientists are searching these areas using ground penetrating radar (GPR)



GPR measures the depth that signals travel before hitting a hidden object



So far, they have found a previously 'undetected pattern' that they claim may indicate a former colonial presence in the area



The mystery of what became of the 120 settlers who tried to establish England's first colony on the north-east coast of America has remained unresolved for 400 years.

Queen Elizabeth I and famed explorer Sir Walter Raleigh had hoped the expedition in the 1580s would create a capital in the New World, but something went terribly wrong.

The men, women and children simply vanished - possibly massacred by native American Indians - and any evidence of a settlement disappeared and the infamous 'lost colony' became rooted in American folklore.

Now, researchers may have c ome a step closer to solving the mystery after enlisting the help of magnetometers and ground-penetrating radar (GPR).

Location, location, location: Roanoke Island is located just off what is now the state of North Carolina (seen in this 16th century map in red). The area of recent interest is the section at the left centre of the map where the two rivers meet

Last year, a centuries-old map of the area drawn by a man on that voyage rekindled interest in the fate of the lost colonists.

Tests found a hint at the possible location of what may have been intended as the colony's capital near Roanoke Island, apparently drawn in invisible ink.

The 'x-marks-the-spot' was shown in the form of a lozenge, the symbol for a fort, on the map drawn by John White, who accompanied Raleigh's first attempt to establish the colony and who led the settlers on their quest to set up the 'Cittie of Raleigh'.

The ink, which is also disguised by a piece of paper glued to it, was likely put together using milk, citrus juice or urine, as was common at the time.

Step back in time: A graphic of the North Carolina coast shows the possible location of the 'Lost Colony' in relation to Roanoke Island, where British settlers established a colony in the 1580s

Were they slaughtered? This painting by White shows native North Americans dancing in a religious ceremony during an expedition in 1585. Many believe the 'lost colony' were massacre by American Indians

Tanya Basu from National Geographic reports that Malcolm LeCompte, a research associate at Elizabeth City State University in North Carolina, came up with the idea to use GPR alongside this map.



Researchers undertook a satellite survey of the site and looked for similarities between the old maps and the current geography of the area.

They are currently identifying where the spots on the map match with today's landscape, before systematically searching the site with their GPR.

Shedding new light: In this close-up of the patch at the centre of the map, a diamond or 'lozenge', the symbol for a fort, can clearly be seen. The symbol was drawn in invisible ink and further concealed with a piece of paper glued on top

Folklore: John White returns to Roanake Island in 1590 to find the settlers have quite simply vanished after he had gone back to England to fetch more supplies

TIMELINE: WHAT WE KNOW SO FAR

1584 — Sir Walter Raleigh's men first land on Roanoke Island and find it suitable for settlement. 1585 — 108 soldiers come to Roanoke to establish first colony. 1586 — Colonists and Native Americans at 'war,' and colony abandoned. 1587 — Second group of 117 colonists come to Roanoke 1590 — Captain White returns to Roanoke to find the colony gone. 1602 — Raleigh makes another attempt to locate the colony. 1921 — The Story of the Lost Colony movie made on site. 1940s — Professional archaeology begins at Roanoke. 2012 - experts identified a tantalising clue hidden in a map drawn by a man on that fateful voyage. 2013 - Researchers study the site with the help of magnetometers and GPR.

GPR works by sending a tiny pulse of energy into a material via an antenna. A computer then records the strength and time required for the return of any reflected signals.

'A GPR unit is somewhat similar to the technology that the police use to measure motorist speed or air traffic controllers use to monitor aircraft,' Professor LeCompte told MailOnline.

'A directional antenna is used to transmit a microwave signal (similar to that used in cell phone transmissions) into the ground. Materials of different density or electrical properties will return the signal at a time dependent on their depth and the medium through which the signal has traveled.



'Denser or more conductive objects will act as antennas reradiating some of the original energy back to the transmitter antenna. The time for this echo to appear provides a measure of the depth as long as the speed of the signal through the ground is known. A void or hollow will reradiate less or no energy and appear dark on the GPR display and in the digital data record.'

Using this technique, Professor LeCompte and his colleagues found a previously undetected pattern that they claim may indicate the presence of one or more wooden structures under about a metre of soil.

Researchers claim the presence of the buried structure may indicate that there was some sort of colonial presence in the area.



The Museum of the Albemarle suggested the use of a proton magnetometer to enable the researchers to double-check their GPR findings, which can find objects buried about 13 feet (four metres) underground.

The device measures distortions of the Earth's magnetic field due to the presence of various objects buried underground. It does this by detecting very small variations in the Earth’s magnetic field.

Researchers are hopeful that it will only be a matter of time before they stumble on further clues to help explain what happened to the Roanoke Colony.