ANCHORAGE, Alaska (AP) — A large amount of valuable information about seismic testing and exploratory wells in Alaska is being released to the public, giving scientists data they need to develop theories about geological formations and making possible oil spots known to drilling companies.

The first of two data sets was released in 2016, and the second is scheduled to go public in the fall, Alaska's Energy Desk reported (http://bit.ly/2h2LaaI ) Tuesday.

The state started collecting the data in 2003 as part of a tax program created for companies to claim a credit in exchange for turning over seismic information and exploratory well data.

The state agreed to keep the data confidential for 10 years — but that time is up.

In total, about 300 terabytes of data is being released. The information is essentially a map of what lies beneath the surface of Alaska.

At least one company is already using the data to plan a drilling operation. That is Nevada-based Alliance Exploration, which plans to start its first drilling operation in Alaska in the winter.

"They were able to access inexpensive seismic data and develop prospects of their own that would lead to exploration and surely, hopefully development," said Mark Wiggin, deputy commissioner of the Department of Natural Resources.

The state is charging $300 per square mile (2.5 square kilometers) for 3-D seismic data, plus another $1.50 per gigabyte. That means getting copies of the data could cost hundreds of thousands of dollars.