OCEARCH is a a data-centric marine research company that has been tracking the shark, dubbed Katherine, and other great whites in the northwest Atlantic. They say Katherine has not appeared on their system since May 2019. It was thought her tracker, which was fitted seven years ago, had run out of batteries.

But information recently “pinged” to their satellite suggested she was lurking approximately off the Virginian coast, in an area they call the Northwest Atlantic Shared Foraging Area (NASFA.)

The NASFA region they refer to is a section of water that extends from Cape Canaveral, Florida, in the south to Cape Hatteras, North Carolina, in the north and from the U.S. coastline in the west to the Gulf Stream in the east. OCEARCH researchers named the region after noticing the majority of tracked northwest Atlantic sharks appeared to stop there at some point in the winter and early spring.

A z-ping is recorded where the shark breaks the surface of the water, but not for long enough that detailed information can be conveyed: “Basically the sends a signal to the satellite, but it is not strong enough to communicate all of the data needed to get a location for the animal,” OCEARCH explains.

The team initially wrote off Katherine’s z-ping as a glitch. However, according to The Charlotte Observer, she then sent three more z-pings, after which they were able to get a very rough idea of where she was located.

“Our satellite tracking provider just did an in-depth analysis of Katharine’s z-pings and was able to produce an extremely rough estimate of where she might be,” the team wrote on April 7, 2020. “The analysis shows there’s a chance she could be about 200 miles off the coast of Virginia.”

According to OCEARCH’s online shark tracker, Katherine’s last official ping was on May 12, 2019 when the tracker located her off the Carolina Coast not far from Charleston.

To alert the tracker, a shark needs to breach the surface for a minimum of 90 seconds and their transmitter has to ping three times in a row, OCEARCH explains. This enables researchers to get an accurate position on the animal. Because individual sharks vary in the amount of time they spend near the surface, some ping more often than others.

However, Katherine’s absence on the tracker may be related to the battery on her transmitter, which—at seven years old—is getting old. According to OCEARCH, the battery on these tags are thought to last up to five years. Before reappearing in May last year, she had been quiet for six months. According to The Charlotte Observer, researchers thought it was because the battery had run out.

Katherine is one of the largest sharks tracked in the region. When she was tagged off Cape Cod in Massachusetts on Aug 20, 2013, she was a sub-adult measuring 14 feet 2 inches and weighing 2,300 pounds. But that was seven years ago, and researchers believe she will have grown since then.

“It’s been seven years. One of the things we don’t understand is the growth rate when they get to this size,” said OCEARCH founder Chris Fischer, The Charlotte Observer reports.

“She’ll be bigger, significantly bigger and in particular, she’s much, much girthier. When they get over 12 feet, they begin to grow girth and body weight. The volume grows quite a bit. She’s probably a very robust, mature female white shark in her productive prime.”

The average length for a female shark is 15 to 16 feet. However, the biggest are known to have reach 20 feet. Katherine, who has her own Twitter account, was named in after Katharine Lee Bates, a Cape Cod native and songwriter known for her poem “America The Beautiful.”