Giant iceberg blocks scientists' study of 'Doomsday Glacier'

Antarctica’s so-called Doomsday Glacier, nicknamed because it is huge and coming apart, is mostly thwarting an international effort to figure out how dangerously vulnerable it is.

A large iceberg broke off the deteriorating Thwaites glacier and, along with sea ice, it is blocking two research ships with dozens of scientists from examining how fast its crucial ice shelf is falling apart.

Scientists from around the world are part of a multi-year $50 million international effort to study the Florida-sized glacier by land, sea and below for the brief time the remote ice is reachable during the Antarctic summer.

Plans to examine the glacier's crucial ice shelf haven't been stopped but are sidetracked a bit, officials said.

This was the last of three international scientific expeditions aimed at the vulnerable ice shelf, said British Antarctic Survey geophysicist Rob Larter, chief scientist of the first research mission.

New York University environmental scientist David Holland, who planned to drill deep through the Thwaites ice shelf to measure the water's warmth below it, is achingly close but not quite there.

Improvising, Holland decamped at the nearby Dotson ice shelf to do his research where no human had been before. He’s hoping that along that blinding white ice and its rugged frozen cliffs he can learn about the unseen warm ocean water nibbling away at both Dotson and Thwaites from below. The smaller Dotson ice shelf is about 87 miles (140 kilometers) west of the Thwaites ice shelf.

The ice shelf “is the most important part of Thwaites and it’s protecting itself and hiding from us,” Holland said in a first video interview from the Dotson ice shelf. He called Dotson’s ice shelf “this beautiful white desert-like landscape, brilliantly white actually. And it will all...