Last week, we told you about a 7,500-square-mile raft of pumice discovered floating in the Pacific Ocean, but more recent observations by NASA reveal that chunks of the volcanic rock have since spread over an area of 100,000 square miles. So people are starting to wonder: What will become of the pumice?

Wired's resident geoscience expert, Erik Klemetti, explains:

This pumice will likely stay afloat for months if not longer and eventually make landfall wherever the currents dictate – potentially as far off as South America. Pumice rafts are not particularly uncommon (see map below), especially in areas of abundant submarine volcanism like the southwestern Pacific Ocean, and they can be fascinating on levels even beyond the volcanology and petrology of the eruption itself. The pumice rafts are like islands that move around the oceans (without the problems of messing with the Orchid station), so you might expect that oceanic organisms will take advantage of their newly created pieces of real estate.

But Klemetti says these are are all just educated guesses. Our understanding of pumice rafts — even recent ones, which have been subject to a fair bit of observation — is limited, but they're remarkably interesting phenomena. For example, in a recent article that examines what happened to pumice produced from an underwater eruption in 2006, a team led by geologist Scott Bryan hypothesizes that these massive rafts may play an important role in the redistribution of organisms throughout the world's oceans.

Read more about the fate of the Havre seamount pumice rafts over at Wired.