29/06/2026 22:58 - Actualidad
An international team of geologists has made an unprecedented discovery: a gigantic geological structure hidden beneath 3 kilometers of ice in East Antarctica. The formation, named the East Antarctic Fan Basin Province (EAFBP), has semi-continental dimensions and represents the most direct evidence to date of how the supercontinent Gondwana fragmented.
Gondwana was a supercontinent that existed between the Neoproterozoic and Jurassic periods, approximately 550 to 180 million years ago. From it derived the continents we know today: South America, Africa, Antarctica, Australia, Arabia, and India. Understanding how it fragmented is fundamental to comprehending the current configuration of continents and oceans.
The study, published in the prestigious journal Nature Geoscience, was led by Egidio Armadillo and included researchers Daniele Rizzello, Pietro Balbi, Alessandro Ghirotto, and Martin Siegert from European universities and institutes.
Scientists identified 30 subglacial V-shaped basins extending radially from a pivot point located at 86.4° south latitude, near the South Pole. The structure spans from Prydz Bay to the Transantarctic Mountains, covering more than 1,500 kilometers.
| Discovery Data | Details |
|---|---|
| Depth | ~3 km under ice |
| Number of basins | 30 subglacial basins |
| Extension | More than 1,500 km |
| Age | ~150 million years |
| Sea level equivalent | 28 meters |
East Antarctica covers more than 99% of its surface with ice, preventing direct access to the rocky bed. Researchers used a combination of advanced techniques: radio echo sounding, gravimetric analysis, and seismic studies to map the subglacial topography with unprecedented detail.
The team proposes that this structure formed through a process of intraplate rotational extension before Gondwana's breakup. Imagine the continent as a fan opening from a pivot point: Earth's crust stretched, generating a zone of lithospheric weakness.
This process had three massive geological consequences:
Researchers note that the rotational extension detected in Antarctica has no continuation in Australia, confirming it was an exclusively Antarctic process.
The identified region harbors approximately half of the East Antarctic ice sheet, with a sea level equivalent of 28 meters.
The subglacial basins, being at several points below modern sea level, can increase the ice sheet's vulnerability to global warming, facilitating the penetration of warm ocean water.
This tectonic heritage from 150 million years ago directly conditions current Antarctic ice dynamics and is fundamental for adjusting sea level projection models.
The identified basins control the location of the continent's main outlet glaciers:
The discovery requires revising reconstructions of the fit between Australia and Antarctica. Current models presented anomalous continental crust overlaps that this new geological framework helps explain.
The most remarkable aspect of this discovery is how geological processes initiated about 150 million years ago directly condition Antarctic ice dynamics today. The basins that formed when Gondwana began fragmenting now guide the flow of the world's largest glaciers.
This knowledge allows scientists to improve predictions about future behavior of the Antarctic ice sheet, one of the most critical elements for understanding sea level rise in the coming decades.
Source: Nature Geoscience | Los Andes
Alfredo S. Quiroga
