Antarctic ice shelf in last throes of collapse

Title: Antarctic [blank_start]Ice Shelf[blank_end] (image) [blank_start]in Last Throes[blank_end] (the last stages; "en las últimas") of [blank_start]Collapse[blank_end] (desintegración, quiebre).

Radar data reveals that the Larsen B ice shelf could [blank_start]shatter into[blank_end] (split into) hundred of icebergs by 2020, researchers reported Thursday (March 14) in the [blank_start]journal[blank_end] (magazine with articles about a subject) Earth and Planetary Science Letters.

"It's really [blank_start]startling[blank_end] (alarming) to see how something that existed on our planet for so long has disappeared so quickly," lead study author Ala Khazendar, a scientist [blank_start]at[blank_end] NASA's Jet Propulsion Laboratory (in Spanish [blank_start]Laboratorio de Propulsión a Chorro[blank_end]) in Pasadena, California, told Live Science.

An ice shelf is like a floating ice [blank_start]plateau[blank_end] (meseta), fed by land-based glaciers.

The ice shelf is on the Antarctica Peninsula, the strip of land (in Spanish, "[blank_start]franja de terreno[blank_end]") that [blank_start]juts[blank_end] (protrudes) northward toward South America.

Because the ice shelf is already in the ocean, its [blank_start]breakup[blank_end] (collapse) won't further boost sea level rise. But Khazendar and his co-authors also discovered that the glaciers feeding into Larsen B's remaining ice shelf have dramatically [blank_start]thinned[blank_end] (se han reducido, han mermado) since 2002.

"What matters is how much more ice the glaciers will [blank_start]dump[blank_end] (throw) into the ocean once this ice shelf is removed", Khazendar said. "Some of these glaciers are most likely already contributing to sea level rise because they are in the process of accelerating and thinning."

The Leppard and Flask glaciers thinned [blank_start]by[blank_end] 65 [blank_start]to[blank_end] 72 feet (20 to 22 meters) between 2002 and 2011, the new study reported. The [blank_start]fastest-moving[blank_end] (más acelerada, con mayor aceleración) part of Flask Glacier [blank_start]sped up[blank_end] (aumentó su velocidad) [blank_start]by[blank_end] 26 percent [blank_start]to[blank_end] a speed of 2,300 feet (700m) year.

But the sotheastern part is cracking up. A huge [blank_start]rift[blank_end] (grieta) has appeared just 7.5 (12 km) from the grounding line (in Spanish, [blank_start]línea de apoyo[blank_end]), where the ice loses contact with the ground and starts floating on the ocean, the study reported. This crack marks where the ice shelf may start to break apart, the researchers said.

This March, the northern tip (in Spanish, [blank_start]extremo[blank_end]) of the peninsula [blank_start]set[blank_end] an unofficial heat record of slightly above 63 F (17 C).

Scientists are tracking the [blank_start]ongoing[blank_end] (that continue) changes in the Antarctica Peninsula ice shelves because the collapse could indicate what may happen across the entire continent.

"Here we have an ice shelf in the process of fragmentation, so we can [blank_start]keep an eye on[blank_end] (watch) it and learn as much as we can about the process before it disintegrates and disappears."

Researchers think the [blank_start]surface warming[blank_end] (in Spanish, calentamiento de la superficie) is melting the ice shelves, [blank_start]triggering[blank_end] (lo que desencadena) a [blank_start]cascade[blank_end] (cascada) of events that eventually leads them to catastrophically collapse.