The remains of an ancient forest were found at the bottom of the ocean, thousands of kilometers from the mainland, where researchers discovered 19 million years old splinters in sediments at the bottom of the Bay of Bengal.
A research team led by Sarah Fickins, from the University of Southern California, drilled the bottom about three kilometers from the surface, collecting sediment from 800 meters below the seabed. By analyzing the sample, the scientists realized how these trees ended up in the ocean millions of years before they were trapped in the ground. The trees grew in most cases in the plain near the ocean, but one layer comes from trees that grew high in the Himalayas, about three kilometers above sea level.
Researchers state that the trees from the ancient forest were uprooted due to a large influx of water, perhaps due to the cracking of a natural dam created by glaciers or a landslide. Those trees covered thousands of kilometers carried by water from cyclones, monsoons or floods, after which they were released into the Bengal delta.
- This is the first proof that trees can be transported thousands of kilometers, from the mountains to the deep ocean – the researchers pointed out.
Their discovery also sheds light on the role of trees in the Earth’s carbon cycle – the way carbon travels from the atmosphere to the planet and its organisms and back. The carbon stored in plants is released when eaten, rotted or burned. Since these trees were transferred shortly after they were uprooted – at the time of death – they did not rot, but fresh wood was trapped in the sediment of the seabed. The new discovery indicates that the amount of organic carbon trapped in the continental margins may be higher than previously thought.
- Rapid transfer and burial of trees is a very effective way to sequester atmospheric CO2 – scientists say, adding that understanding the amount of carbon trapped as a result of forests that have ended up in the ocean is important for understanding future climate change.
Scientists are currently working on understanding the carbon cycle, with American researchers who launched the Deep Carbon Observatory (DCO) program about ten years ago. A recent report by the group showed that above the Earth’s surface – in the oceans, soil and atmosphere – there is less than one percent of the total amount of carbon. The rest is trapped in the crust, mantle and core of the planet.