Tectonic Plates Drive Marine Biodiversity Every 36 Million Years, Study Finds
Researchers have discovered that tectonic plates, massive slabs of slowly-moving rock beneath the Earth’s surface, play a significant role in driving bursts of marine biodiversity every 36 million years. According to a new study published in the journal PNAS, the movement of these plates causes sea levels to rise and fall, consequently creating new habitats for ocean life to thrive.
The study’s co-author, Professor Dietmar Müller from the University of Sydney, explained in an interview with Live Science that warm, shallow water environments are crucial for the development of marine biodiversity. The researchers found that the cyclical flooding and drying up of continents, which has occurred for at least 250 million years, provides fertile grounds for marine life to flourish.
The slow movement of tectonic plates is the key factor behind the creation of these prolific habitats. In regions known as mid-ocean ridges, the Earth’s mantle pushes the plates away from each other, resulting in the formation of new oceanic crust through a process called seafloor spreading. In other areas, the collision of tectonic plates causes one to slide beneath the other, leading to the pulling of ocean water into the Earth’s mantle. This process lowers sea levels and alters the elevations of the ocean floor, which in turn affects sea-level rise.
According to Müller, the speed at which seafloor spreading and subduction occur impacts the fluctuation of sea levels. When there is significant creation and destruction of seafloor, sea levels peak. Conversely, when the system slows down, sea levels reach lows. During periods of rising sea levels and coastal flooding, shallow pockets of seas are formed, providing ideal conditions for the emergence of new species.
The researchers analyzed plate tectonic movements and sea-level changes, comparing them with marine fossil records dating back 250 million years. Through their analysis, they discovered a correlation between tectonic changes that drove shallower sea levels and highly biodiverse periods recorded in the fossil data. Essentially, peak sea level rise coincided with a peak in marine biodiversity.
Müller emphasized that the research provides compelling evidence that global sea level change, driven by Earth’s geological processes, has a profound impact on the biodiversity of marine life throughout history.
The study underscores the importance of accessing vast amounts of data within the Paleontology Database, which has the potential to revolutionize the field. Gareth Roberts, a senior lecturer in Earth Sciences at Imperial College London, described the study as another crucial step in understanding the evolution of marine fossil diversity over time.
However, the researchers noted that shifting tectonic plates are not the only factor influencing sea levels and biodiversity. Human-caused climate change, which is heating up ocean temperatures and melting ice sheets, is also contributing to a rise in sea levels. Müller cautioned that sea-level rise and coastal flooding could occur much more rapidly than the 36 million-year cycle due to this human-induced climate change.
In summary, the study reveals the significant role played by tectonic plate movements in driving marine biodiversity every 36 million years. The findings contribute to a growing body of evidence suggesting that global sea level change influenced by Earth’s geological processes has shaped the diversity of marine life throughout history.