Earth’s crust is dripping like honey. It has been going on for millions of years

Scientists have for the first time discovered a unique development happening under the Andes, the longest continental mountain range in the world — the crust beneath is dripping like honey and it has been happening for millions of years. The material is being consumed by the mantle, the layer beneath the crust.

Researchers found that the rocky outermost layer of Earth’s shell is continuously sinking into the more fluid layer of the planet’s mantle in a process called lithospheric dripping. This is resulting in significant deformations on the surface leading to the creation of basins, folding of the crust and irregular elevations.

Earth’s surface has three layers, the outermost being the crust, the middle is the mantle and the innermost region is called the core.

The study published in the journal Communications Earth & Environment states that the basin and plateau regions of the Central Andes have undergone phases of rapid subsidence and uplift during the last 20million years in addition to internal tectonic deformation.

“The formation of the Arizaro Basin and nearby Central Andean basins are caused by symptomatic lithospheric dripping events and highlight the significant role of non-subduction geodynamic mechanisms in driving surface tectonics,” researchers concluded in the paper.

While the findings are new to the world of plate tectonics, lithospheric dripping has been noticed around the world including in the Central Anatolian Plateau in Turkey and the Great Basin in the western US. Researchers led by scientists at the University of Toronto have confirmed that several regions in the central Andes Mountains in South America were formed the same way.

“We have confirmed that deformation on the surface of an area of the Andes Mountains has a large portion of the lithosphere below avalanched away. Owing to its high density, it dripped like cold syrup or honey deeper into the planetary interior and is likely responsible for two major tectonic events in the Central Andes shifting the surface topography of the region by hundreds of kilometers and both crunching and stretching the surface crust itself,” Julia Andersen, lead author of the paper said in a statement.

Scientists believe that the phenomenon happens when portions of the lowest layer of Earth’s outer shell thicken and begin to drip into the mantle below when warmed to a certain temperature. As it sinks it first forms a basin at the surface which later springs up when the weight below breaks off and sinks further into the deeper depths of the mantle.

The team developed models to recreate the conditions and situations to understand what happened thousands of centuries ago that led to the modern-day mountains in the region. The researchers suggest the findings aim to clarify the link between mantle processes and crustal tectonics.

“The discoveries show that the lithosphere can be more volatile or fluid-like than we believed,” Earth sciences Professor Russell Pysklywec, co-author of the study concluded.