Tinytag Data Logger Project | Monitor Cave Condition to Reconstruct Past Climate Change (4/23/2016)

Climatic changes are being investigated by monitoring environmental conditions in caves using temperature data loggers, while a drip counter based on a Tinytag count logger investigates the relationship between rainfall and the formation of stalagmites.

Prof. Dave Mattey of the Department of Earth Science, Royal Holloway, University of London, is using Tinytags to measure climatic changes by monitoring inside caves.

We are all aware of the uncertainties regarding the future of the Earth's climate systems. Weather forecasting can be rather imprecise and predicting the future behaviour of global weather patterns rests on computer models that rely on meteorological data and an understanding of what drives weather systems. However, meteorological records only stretch back a century or so, and our understanding of how the global climate systems interact and change is far from complete.

Geologists are researching new ways to use chemical records in rocks and fossils to monitor climate change in great detail, which will lead to improved predictions of future changes. One of these chemical records can be found in caves in the form of stalagmites that grow from water that has fallen as rain. Stalagmite 'weather stations' can be accurately dated and steadily grow in a stable undisturbed environment for many tens of thousands of years and are turning out to be very valuable archives of past weather patterns.

Professor Dave Mattey of the Department of Earth Science, Royal Holloway, University of London, is using Tinytag data loggers to measure the subtle changes in the environment inside the cave that occur over many years. He is leading research focussed on how changing weather above the cave affects the growth of stalagmites and the chemical 'memory' preserved in the stalagmite of the rainfall, outside temperature and the type of vegetation. Using rugged Tinytag Plus 2 data loggers, measurements are made in many locations inside and outside the cave at hourly intervals, giving unprecedented levels of detail.

Caves provide a very harsh environment where 100% humidity can cause relentless corrosion and instrument failure due to damp and condensation. Caves are often remote, with no power, and have difficult access, requiring rugged instruments that will provide a reliable data over long time periods. The battery powered Tinytag temperature loggers have proved very reliable in measuring seasonal changes in air and rock temperatures inside caves and also in the overlying soil where they have been buried at different depths for up to a year before data is downloaded.

Another area of interest is the relationship between rainfall and the formation of stalagmites. Research has focussed on the time taken for groundwater saturated in calcium carbonate to penetrate through the soil and bedrock into the cave. If the cave starts dripping soon after a period of rainfall then the stalagmite 'weather station' records day to day changes in climate; if the dripping takes a long time to build up, or just remains constant all year round then the 'weather station' is recording more gradual changes, smoothing out the day-to-day variations.

The research team has developed a unique logging drip counter, the 'Stalagmate' (pictured), which is based on an OEM version of the Tinytag count logger and a sensor built into a waterproof box that is placed on top of stalagmites to show precisely how drip rates respond to rainfall. The Stalagmate is commercially available and large numbers are now in use in caves and for groundwater research worldwide.

Cave and climate research using Tinytag data loggers has been carried out in Europe, India and the south Pacific. The Tinytags and the OEM count loggers have proved their worth despite the appalling treatment they are sometimes subjected to! Other than a battery change every year or so, they have worked reliably in humid caves, buried in soil, and sometimes submerged in water and returned data without any problems.

Dave Mattey is Professor of Geochemistry at Royal Holloway, University of London and has been director of the Stable Isotope Facilities since 1989. He leads research into cave science and climate reconstruction in Europe, India and the Pacific.