The Galapagos National Park published a series of photographs this week showing molten lava flowing down the slopes of the Wolf volcano beneath a plume of thick smoke. Wolf lies on the archipelago's biggest island, Isabela, and had been dormant for the past 33 years.

Sandro Vaca of Ecuador's Geophysics Institute says the volcano's activity is likely to continue for several days, although it poses no danger to the island's human population. The nearest inhabitants live in the town of Puerto Villamil, some 115 kilometers (70 miles) south of the volcano.

There are five active volcanoes on Isabela: Wolf, Sierra Negra, Cerro Azul, Darwin and Alcedo. According to the national park authorities, Wolf's first recorded eruption happened in 1797. There were 10 subsequent eruptions, including the last in 1982. In April, unusual seismic activity was reported at the Sierra Negra volcano.

Like much of the Galapagos archipelago, Isabela Island is home to a rich variety of wildlife. For example, it's the only place in the world where the endangered pink iguana can be found. The Galapagos National Park said the iguanas probably won't be harmed by the eruption because the colony lives on the volcano's northwestern flank - away from the lava flows.

Tortoises, yellow iguanas and penguins are other species also found on the island. Charles Darwin famously visited the Galapagos archipelago in 1835 during his voyage aboard the Beagle. The trip and his observations of the local plants and animals contributed to his theory of evolution by natural selection later presented in his work, The Origin of the Species.

The Galapagos Islands are situated in the Pacific Ocean about 906 kilometers (563 miles) off the coast of Ecuador. The islands became a national park in 1959 and tourism began to grow soon afterwards. The surrounding waters were declared a biological marine reserve in 1986. In 1978, UNESCO recognized the islands as a World Heritage Site.