Scientists Discover New Lava Eruptions from Earth’s Mantle as a New Ocean Forms

Deep beneath our planet, heat gathers in a layer called the mantle. This heat causes rocks to rise slowly toward the surface, a process known as mantle upwelling. This movement is crucial for creating volcanoes, separating continents, and forming new ocean basins.

One interesting area for geologists is the Afar Depression in East Africa. Here, three tectonic plates meet: the Main Ethiopian Rift, the Red Sea Rift, and the Gulf of Aden Rift. This unique intersection provides insights into the earth’s internal processes.

Scientists have been aware of this upwelling for some time but lacked clear information about its shape and behavior. Recent studies, however, have made significant strides. Researchers from the University of Southampton collected lava samples from over 130 young volcanoes in the region. Analyzing the chemistry of these samples has revealed that the upwelling is not just a simple column of rising material. Instead, it’s quite complex, with varying hot mantle materials that resemble a patchwork quilt.

Emma Watts, the lead author of the study, said, “The mantle beneath Afar is not uniform or stationary – it pulses, and these pulses carry distinct chemical signatures.” This means the hot material can rise more easily where the tectonic plates are stretching. This process not only leads to volcanic activity but also aids in the development of new ocean basins.

Tom Gernon, a co-author on the research, likened the chemical variations to a heartbeat. He noted that the flow of mantle material changes depending on how quickly the tectonic plates are moving apart. In regions like the Red Sea Rift, where the plates move rapidly, the mantle flow is more concentrated. Conversely, in areas with slower movement, the flow is more diffused.

The connection between mantle chemistry and plate dynamics reshapes our understanding of how continents fracture. Co-author Derek Keir from the University of Florence emphasized that the movement of tectonic plates significantly influences surface volcanic activity and earthquake occurrences.

The hot mantle plume is actively eroding the lithosphere, the Earth’s outer shell, sometimes thinning it to just 15 kilometers. This thinning, along with the pulling action of plate movements, causes periodic volcanic explosions.

Volcanic activity in Ethiopia is already evident. Lava flows cover extensive areas, and seismic activity indicates new crust formation. Over time, researchers predict that seawater will invade, splitting the Horn of Africa from the mainland, much like the Atlantic Ocean separated from Europe and North America millions of years ago.

Historically, large igneous provinces, like the North Atlantic Igneous Province, have caused significant climate changes due to massive CO2 emissions, potentially triggering mass extinctions. Thus, understanding the behavior of the Afar plume has broader implications for predicting past and future environmental changes.

Researchers aim to further explore mantle flow beneath thin tectonic plates and how it influences volcanic vents. Watts concluded that collaboration among scientists with various expertise is vital for understanding these complex processes beneath the Earth’s surface.

In summary, the study not only sheds light on mantle upwellings but also demonstrates their relationship with tectonic activity. These findings allow us to hear the rhythmic signals of Earth’s deep forces, painting a picture of a continent slowly being torn apart and an ocean waiting to form.

The research has been published in the journal Nature.

For more information, you can read the study here.

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