Scientists have actually generally relied on sediment records from lakes to rebuild records of previous fires. But what do you do with dryland areas that do not have lakes? Traditionally, there was very little information regarding previous fires in these areas. A new research study has actually found that sand dunes can likewise serve as a repository of fire history.
The Cooroibah wildfire sweeps down the Cooloola Sand Dunes in Australia. Image credits: Michael Ford.
The scientists wished to show that sand dune deposits could be utilized to develop fire histories. “Many fire and paleoclimate records are situated where theres a great deal of water bodies such as bogs, lakes, and peats. Since of this, many worldwide designs truly have a bias towards temperate regions,” study author Nicholas Patton said in a statement.
Australia is one of the worlds most fire-prone landscapes, with substantial areas without lakes or ponds to collect sedimentary records from.
The research study is the very first one to take a look at sedimentary records preserved in foot-slope deposits of sand dunes for this purpose. The research group studied 4 dune at the Cooloola Sand Mass in Australia, a large coastal dune field.
Sand dunes records
The younger dunes (500 and 2,000 years old) had unique layers of charcoal that represented individual fires, the researchers found. The high slopes of these dunes buried each layer, preserving them individually. The older dunes (5,000 and 10,000 years of ages) had rather more gradual slopes, resulting in charcoal from various fires mixing together.
The scientists recommend that comparable records most likely exist in sand dunes worldwide, emphasizing the potential advantages of comprehending local fire history in areas like California and the Southwest United States. Within these fire records, valuable info can be found not just about natural wildfires but also about the influence of human activities on fire routines.
The research study was published in the journal Quaternary Research.
The Cooloola Sand Mass features huge dune as high as 240 meters. These form along the shoreline and gradually move inland due to the force of the wind. Using a method called optically promoted luminescence dating (OSL), the researchers discovered that the four dunes span the Holocene duration, encompassing the last 12,000 years.
” We were digging soil pits at the base of the dunes and were seeing a lot of charcoal– more charcoal than we anticipated,” Patton said in a declaration. “And we believed possibly we could use these deposits to rebuild regional fires within the location.”
As the four dunes used localized fire histories within a radius of 100 meters, fire records differed to some degree. To confirm their findings, the scientists compared their results with other fire records stemmed from lake and overload deposits. Extremely, their findings lined up with the local records, revealing 3 periods of fire activity. This essentially confirmed that dunes can be record-keepers of local fire occasions.
Once a dune reaches a steady state, where it stops to grow and starts to gradually wear down, the force of gravity enters into play. Gravity causes the sand and residues of charcoal from regional fires, which collect on the dunes surface, to collect at the base. Over time, this sediment develops, forming layers of charcoal from various fire events.
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The researchers wanted to show that sand dune deposits could be utilized to construct fire histories. Gravity triggers the sand and remnants of charcoal from regional fires, which collect on the dunes surface area, to collect at the base. The younger dunes (500 and 2,000 years old) had unique layers of charcoal that represented specific fires, the researchers found. As the four dunes used localized fire histories within a radius of 100 meters, fire records varied to some extent.
A new study has actually found that sand dunes can also serve as a repository of fire history.