Igor Shpilenok / Steaming fissures and geysers in the caldera of Uzon Volcano, Kronotsky Zapovednik, Kamchatka, Far East Russia

Heather Angel / Paraquilegia (Paraquilegia microphylla) growing in rock fissures with crustose lichen. On cliff, Baimashan, Sichuan Province, China.

Doug Perrine / Lava from Kilauea Volcano erupts from fissures in Kapoho, shooting glowing lava bombs hundreds of meters into the sky and releasing clouds of poisonous gases. Puna District, near Pahoa, Hawaii. June 2...

Doug Perrine / River of lava flowing through Puna District, with vegetation on the downwind side of the lava river (lower left) which has been killed by toxic fumes emitted by the lava. This lava erupted fissures in...

Doug Perrine / Lava emanating from Pu'u O'o, Kilauea Volcano, erupting from multiple fissures in Leilani Estates, near Pahoa, Puna, Hawaii. The fissure in the lower part of the frame is Fissure 8, which became the d...

Michel Roggo / Mountain climbers on the Gorner Glacier with fissures and eroded rocky ground, Valais Alps, Canton Valais / Wallis, Switzerland. August. Photographed for The Freshwater Project

Michel Roggo / Gorner Glacier with fissures and eroded rocky ground, Valais Alps, Canton Valais / Wallis, Switzerland, August. Photographed for The Freshwater Project

Nick Upton / Trees and maquis vegetation growing in gulleys and fissures on the steep, volcanic rocky headland of Cape Senino between the Gulfs of Girolata and Porto, part of a UNESCO World Natural Heritage Site w...

Franco Banfi / Hot sulphur released as crystal clear bubbles due to small fissures on the sea bed, Champagne Reef Diving place, Dominica, Caribbean Sea, Atlantic Ocean.

Staffan Widstrand / Seasonal marshlands which had dried up, Pulicat Lake, Tamil Nadu, India, January 2013.

Bryan and Cherry Alexander / Deep shaded fissures in an iceberg, Antarctica, February 2009.

Nick Upton / Trees and maquis vegetation growing in gulleys and fissures on the steep, volcanic rocky headland of Cape Senino, part of a UNESCO World Heritage coastal/marine site within Corsica's National Park (Pa...