near Ballycastle, Northern Ireland
The remote upland lake of Loughareema in Co. Antrim is known to most people in Northern Ireland as the vanishing lake. It’s not surprising to find out that it is an ephemeral lake that fills and empties with relative rapidness. One day it could be empty, and the next, completely full. As you pass along the road that runs through the lake, it is exciting to guess what state it will be in. This makes the landscape appear dynamic and alive.
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ts bleak and isolated location means that it is frequently shrouded in fog, coupled with the fact that it is surrounded by bleak blanket bog means that it is not the most inviting place to stop for a picnic.To most people, Loughareema is best known for its ghost stories.
Local legend tells us of the drowning of a coach and horses in the 19th century as they tried to cross the lake when it was full. Bizarrely, a road had been built through the lake when it was empty so in the dead of night it was impossible to tell if water levels were high or low. It is said that on nights when the lake is full, a phantom ghost haunts the shoreline, and together with the prospect of the sight of a kelpie, or water-ghoul, Loughareema is not short of a story.
To scientists, Loughareema is regarded as one of Northern Ireland's most enigmatic geological sites. The lake has three streams flowing in to it but none out. A sink at the base of the lake drains all of the water out of the lake in to an underground drainage system. This water reappears some 2.5 km away from a large spring in to the Carey River. Its drainage system is not yet well understood. The sink should have formed in outlying Cretaceous Ulster White Limestone but basalt is seen outcropping within 10 m of the sink.
The mechanism for drainage at Loughareema has baffled scientists for years, adding to the mystery of the site, but all of that is about to change. Dr Paul Wilson, an expert in the distribution and movement of water within rocks with the British Geological Survey, has recently embarked on a detailed study of Loughareema. He explains more:
"Loughareema is a dynamic landscape and on approach to the lake it's exciting to guess what state it will be in. The water disappears into an underground drainage system, the details of which we currently know very little about. This new study will be in two parts; the first uses a camera to take time lapse images of the lake, hopefully capturing it filling and emptying; the second will use water level loggers at various location to measure the rate that the lake is filling and emptying."
The study is ongoing and the first images from the time lapse photography are beginning to come through, recording for the first time the emptying and filling of the lake. This exciting project perhaps won't shed any light on the ghosts of Loughareema, but it will be able to solve the mystery of the disappearing water, and lead to a better understanding of the entire drainage system.
Text: Dr Kirstin Lemon at Geological Survey Northern Ireland