Japan’s aftershocks are continuing, although they’re gradually slowing, according to Caltech officials Saturday.

More than 200 earthquakes have occurred over the past week, in addition to Friday’s 9.1 megaquake, according to officials.

“We have recorded 200 earthquakes of magnitude 5 or larger in this sequence,” said Lucy Jones of the U.S. Geological Survey at Caltech’s briefing Saturday.

“We’ve had about 30 magnitude 6’s,” she added, including one smaller quake that briefly interrupted the briefing.

While the earthquakes will continue for a few more days, she said they’re leveling off at the same rate as other earthquakes — a sign that this megaquake isn’t an anomaly but just a larger quake than typical.

“They’re continuing at a pretty rapid pace and that number will be growing throughout the day,” she said.

Jones stressed the importance of the data to scientists and said this is the most thoroughly documented earthquake in human history.

“This is overwhelmingly the best recorded big earthquake … ever, by a long shot,” she said. “Scientists are being mobilized around the world.”

Tom Heaton, a professor of engineering at Caltech, explained that while Japan rest on the world’s busiest fault lines, large earthquakes are still extremely unusual.

“There’s a very long history of earthquakes in Japan,” he said. “So in Japan, when people looked at this great fault, and you can’t ignore it, they saw [they] don’t have any historic records of great earthquakes.”

“As a result, in the zoning for the hazards of Japan, this was viewed as a relatively lower hazard,” he continued. “The deduction was [the fault] must be slowly creeping along, there’s no way you could have such an enormous fault go for an entire millennium without great earthquakes.”

He said the quake means scientists had their information wrong all this time as well.

“Now we see a truly giant earthquake in the zone,” said Heaton. “The next month or so, the scientists will be scrambling trying to figure out, ‘How do we reassess this entire subduction zone? How do we actually understand what’s going on in this place?’”

He said this means the plethora of new information collected from the megaquake will be used a great deal to plan for the future, and that Caltech would be studying those numbers for the weeks to come, looking for trends.