New London — Just over 200 icebergs drifted into North Atlantic shipping lanes in 2018, considered a "light" ice season, breaking a streak of three "extreme" ice seasons.

The New London-based Coast Guard International Ice Patrol, which monitors iceberg danger in the North Atlantic and sends out warnings to the maritime community, provided an update on the 2018 ice season during its annual meeting Wednesday at its office on Chelsea Street.

Two-hundred and eight icebergs drifted into North Atlantic shipping lanes in 2018 compared to 1,065 in 2015; 678 in 2016; and 1,008 in 2017.

Ice season usually runs from early February through the end of July, with the peak usually occurring in May and June. An extreme ice season occurs when more than 600 icebergs enter the shipping lanes.

There was a "rapid" decline in sea ice from late February through early March 2018 due to above-normal air temperatures from October through January 2017, which, combined with a series of powerful low-pressure systems, drove sea ice growth below the average level beginning in late February, according to the report.

During ice season, the Ice Patrol actively patrols the area around the Grand Banks of Newfoundland, tracking icebergs as small as 15 meters in length up to those that are hundreds of meters in length, and produces daily iceberg warnings. Last year's extreme ice season caused detours and added travel times for mariners in an already heavily trafficked area.

The shortest course between northern Europe and North America is about 2,300 miles, an area that experiences a "tremendous" amount of commerce, said Cmdr. Kristen Serumgard, who heads the Ice Patrol.

"As our limit expands, ships have to go further south. This could mean a 24 to 36 hour change in arrival time. ... that's a huge impact on maritime commerce," Serumgard said.

Iceberg detection and identification is mainly carried out by Coast Guard aircraft, but ice patrol increasingly is using satellite technology. Accuracy is still an issue — just because a satellite doesn't show an iceberg doesn't mean one isn't there, Serumgard said. The Ice Patrol also receives reports of icebergs from commercial aircraft and mariners in the North Atlantic.

j.bergman@theday.com