Our directory of things of interest

University Directory

Prehistoric caves provide clues to climate change

Stalagmites provide a clue to historic climate conditions Stalagmites provide a clue to historic climate conditions wjarek
31 Jul
Underground water movement in caves reveals climate action above

When water seeps into the ground it picks up minerals, usually calcium carbonate. This mineral-rich water can drip into caves, leaving mineral deposits behind. These deposits can be dated through radioactive decay.

Variation in the thickness of layers can tell researchers how much precipitation occurred over time. With one more twist, using the ratios of heavy to light isotopes of oxygen present in the layers, researchers can find the temperature at which the water originally condensed.

Researchers have used the technique to examine the Mawmluh Cave in the Indian state of Meghalaya, an area thought to be the rainiest place on Earth. The technique helped to establish a relationship between monsoon rainfall and sea surface temperatures in the Pacific Ocean, known as the El Niño Modoki.

‘Now that we have shown that the Mawmluh cave record agrees with the instrumental record for the last 50 years, we hope to use it to investigate relationships between the Indian monsoon and El Niño during prehistoric times such as the Holocene,’ says Jessica Oster, a researcher who worked on the project.

The Holocene saw a period of global climate warming around 6,000 to 9,000 years ago. Temperatures were four to six degrees higher than today, around the increase predicted if human-caused global warming continues unchecked.

Understanding the historical monsoon patterns could help researchers predict how it will change in the future. The monsoon provides the area with 75 per cent of its annual rainfall.

The researchers used stalagmites with high concentrations of uranium for the analysis, including columns that had probably broken off in an 8.6 magnitude earthquake that hit Assam in 1950. The new stalagmite growth was perfect for analysis.

Related items

Subscribe and Save!

geo line break v3

Free eBooks - Geographical Newsletter

Sign up for our weekly newsletter today and get a FREE eBook collection!

geo line break v3

University of Winchester

geo line break v3


Aberystwyth University University of Greenwich The University of Derby




Travel the Unknown

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in NATURE...


A look at the contribution of hippos to the savannah…


The new app encourages young children to connect with the…


A type of panel has been invented that can generate…


In the 4th century BC, Aristotle proposed that earthquakes were…


The Chartered Institution of Water and Environmental Management pledges to achieve net…


Earthquakes from time immemorial have attracted the attention of the…


A planned kayaking expedition in Nepal took on a whole…


Scientists from Bristol University are working in conjunction with EDF…


In the 1930s, Charles Richter developed a simple scale for…


Researchers at Colombia University have answered a question that has…


How prepared can any government or city be against a…


Benjamin Hennig creates a series of cartograms to demonstrate the…


Could grey seals singing Twinkle Twinkle Little Star help develop…


Deep sea expert Dr Alex Rogers explains the importance of…


Analysis of coral cores, extracted from coral reefs in the…


Celebrities and animal welfare groups have been expressing their disappointment…


In a series of photographs from his recent trip to…