Nav: Home

Caves in central China show history of natural flood patterns

January 19, 2017

Researchers at the University of Minnesota have found that major flooding and large amounts of precipitation occur on 500-year cycles in central China. These findings shed light on the forecasting of future floods and improve understanding of climate change over time and the potential mechanism of strong precipitation in monsoon regions.

The research is published in the published in the Proceedings of the U.S. National Academy of Sciences (PNAS), a leading scientific journal.

"To predict how climate change will impact the future, it's important to know what has happened in the past," said Joshua Feinberg, a University of Minnesota associate professor of Earth Sciences and associate director of the Institute for Rock Magnetism, who supervised the research.

"As the variability and intensity of storms increase in the world, we need to reevaluate what the frequency of these major storms could be," Feinberg said. "We didn't have the potential to develop these kinds of precipitation records for most of the world, until now. These speleothems provide more than 8,000 years of data that led us to identify with strong confidence the presence of a 500-year cycle," he added

The research used stalagmites collected from Heshang Cave in central China within the Yangtze River drainage. Researchers measured the magnetic properties of layered stalagmites, or columnar mineral deposits formed in caves by the growth of carbonate minerals from dripping groundwater. As they form over time, stalagmites develop annual layers of the mineral calcite, which are broadly similar to the rings of a tree. They also collect iron-rich magnetic materials within these layers, which originated in overlying soil and are transported into the cave during precipitation and flooding events. These iron-rich minerals are far less than the width of human hair in size, but produce a strong magnetic signal that can be easily measured by modern magnetometers.

Feinberg and his team analyzed the magnetic properties of the layered stalagmites and discovered more than 8,000 years of data within the materials. The magnetic data varied in such a way as to trace out a 500-year cycle of storm variation, where wetter intervals showed an increased concentration of magnetic minerals. This correlates well with the cycles of El Niño Southern Oscillation pattern and measured changes in the amount of the energy from the sun. The cycle can be used to anticipate broad precipitation patterns in the future, and provide insight on climate change in the region over time. Feinberg and his team hope to expand this work wherever possible around the globe.

With the help of the Institute for Rock Magnetism (IRM), based at the University of Minnesota, the group was able to measure the magnetic materials within the speleothems to at a higher resolution and sensitivity than previously possible. Many rocks record the direction and strength of the Earth's magnetic field at the time of their formation. By measuring these magnetizations, researchers are able to show how tectonic plates have moved around the globe through time, as well as how the Earth's magnetic field has varies over timescales ranging from millions of years to decades. The short-term behavior of the Earth's magnetic field has important ramifications for satellites and satellite communication.
-end-
Postdoctoral research associates Zongmin Zhu and Mark Bourne, IRM and Department of Earth Sciences; research scientist Hai Cheng, Xi'an Jiatong University; and Shucheng Xie, Chunju Huang and Chaoyong Hu, researchers from the China University of Geosciences are co-authors of the study.

The research was financially supported by the National Natural Science Foundation of China, State Key R&D program of China, and the 111 program (National Bureau for Foreign Experts and the Ministry of Education of China). The Institute for Rock Magnetism is funded by the U.S. National Science Foundation (NSF) Division of Earth Sciences Instruments and Facilities Program and the University of Minnesota. Feinberg's research is funded by NSF-EAR1316385.

To read the complete study entitled "Holocene ENSO-related cyclic storms recorded by magnetic minerals in speleothems of central China," visit the PNAS website.

For more information about the Institute for Rock Magnetism, visit http://www.irm.umn.edu.

University of Minnesota

Related Climate Change Articles:

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Processing The Pandemic
Between the pandemic and America's reckoning with racism and police brutality, many of us are anxious, angry, and depressed. This hour, TED Fellow and writer Laurel Braitman helps us process it all.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Invisible Allies
As scientists have been scrambling to find new and better ways to treat covid-19, they've come across some unexpected allies. Invisible and primordial, these protectors have been with us all along. And they just might help us to better weather this viral storm. To kick things off, we travel through time from a homeless shelter to a military hospital, pondering the pandemic-fighting power of the sun. And then, we dive deep into the periodic table to look at how a simple element might actually be a microbe's biggest foe. This episode was reported by Simon Adler and Molly Webster, and produced by Annie McEwen and Pat Walters. Support Radiolab today at Radiolab.org/donate.