A volcanic eruption in southwest Iceland has prompted evacuations, including at nearby tourist sites like the Blue Lagoon.

       The Sundhnukur volcano, located on the Reykjanes Peninsula, began erupting early Wednesday morning, according to officials.

       After two hours of seismic activity, the volcano began erupting at the Sundhnukur crater range -- about 30 miles southwest of Reykjavik -- just before 4 a.m. local time, the Icelandic Meteorological Office announced.

       A fissure about 1.5 miles long opened up at the Sundhnúkur crater row as a result of the eruption, aerial surveys by the Icelandic Coast Guard showed. A second, smaller fissure measuring about .3 miles was created west of Fagradalsfjall, according to the Met Office.

       "Witch's hair" -- strands of volcanic glass often produced by lava fountaining activity, also referred to as "Pele's hair" -- was seen drifting in the wind, the Met Office said. Contact with the material can cause skin and eye irritation.

       In addition, high levels of gas pollution were measured nearby in Reykjanesb？r, but levels were decreasing in the hours after the eruption began, officials said.

       Places like Grindavik, a nearby fishing town, and the Blue Lagoon, the geothermal spa that is one of the country's most iconic tourist sites, were among the locations instructed by officials to evacuate, public broadcaster RUV reported.

       The town of Grindavik has experienced repeated threats in recent years after the once-dormant volcano on the Reykjanes peninsula began erupting again after 800 years of no activity.

       Iceland is known as a hot spot for volcanic activity. There are 32 active volcano systems in the region spread across three rift zones, all part of the Mid-Atlantic Ridge, a mountain range that mostly runs down the middle of the Atlantic Ocean.

       In addition, there is an "excessively high production of magma" in the region, Thomas Algeo, a professor of earth sciences at the University of Cincinnati, told ABC News in November after the eruption triggered evacuations at Grindavik and the Blue Lagoon.

       West Iceland's volcano is a rift activity volcano, which involves the earth being pulled apart in two different directions through the Mid-Atlantic Ridge, rather than a cone erupting magma through a central pipe, Algeo said.

       Once the lava erupts, the pressure is relieved and magma starts to fill into the shallow storage zone below -- repressurizing the system and setting the stage for the next eruption.

       The style of eruption is "much less dangerous, because most of the activity involves slow-moving basaltic lava flows," Algeo said.

       These types of eruptions offer "spectacular" views because large supplies of magma ooze out of the fissures once they open up, Tobias Fischer, director of the Volatiles Laboratory at the University of New Mexico, told ABC News in November.

       There have been 11 eruptions at the volcano in southwestern Iceland since it became active again in 2021, according to the Met Office.

       Iceland's western rift zone, also known as the Reykjanes-Langj？kull rift zone, was active prior to the 13th century. Fischer said. These types of eruptions tend to occur every 1,000 years or so.

       During the last 800 years, the majority of volcanic activity has been in the north and east volcanic zones -- both lightly populated regions. However, western Iceland, which includes he capital of Reykjavik, is highly populated.

       The location of the latest eruption is favorable because lava flows will likely not threaten any infrastructure, Minney Sigureardóttir, a natural hazard specialist at Met Office, told RUV.