The Fuego volcano is seen from Alotenango municipality, Sacatepequez department, about 30 km southwest of Guatemala City, as it erupts on May 5, 2017. Authorities evacuated 300 people threatened by an erupting volcano in southern Guatemala on Friday, emergency services said. The so-called Volcano of Fire was spitting hot ash thousands of meters into the air, the National Volcanology Institute said. (Photo by Johan Ordonez/AFP Photo)





Motorists ride along a road as Mount Sinabung volcano spews thick volcanic ash, as seen from Tangkulen village in Karo, on May 12, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Tibta Pangin/AFP Photo)





Mount Etna, Europe's most active volcano, spews lava as the Sicilian town of Riposto, Italy, is visible in foreground, during an eruption in the early hours of Tuesday, April 11, 2017. (Photo by Salvatore Allegra/AP Photo)





Mount Sinabung volcano spews thick volcanic ash as seen from Tiga Kicat village in Karo, North Sumatra province, on early May 6, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Tibta Pangin/AFP Photo)





Costa Rica, Alajuela, La Fortuna. The Arenal Volcano. Although classed as active the volcano has not shown any explosive activity since 2010. (Photo by Nick Ledger/Getty Images/AWL Images)





Eruptive activity on Etna volcano where lava flows down towards the valley on March 27, 2017 in Sicily, Italy. (Photo by Marco Restivo/Barcroft Images)





Mount Sinabung volcano spews thick volcanic ash as seen from Beganding village in Karo on early May 2, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Tibta Pangin/AFP Photo)





Mount Sinabung volcano spews thick volcanic ash as seen from Beganding village in Karo, Indonesia on early May 2, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Tibta Pangin/AFP Photo)





Mount Semeru, Mount Bromo and Mount Batok are three sacred volcanoes on Java, Indonesia, that have shaped both the culture and the landscape of the region. These incredible geological formations were published as part of our story “The Gods Must be Restless” in the January 2008 issue of National Geographic magazine. (Photo by John Stanmeyer/National Geographic Creative)





Lava flows down the ridges after a spectacular volcanic eruption from Mount Etna on April 27, 2017 in Catania (Sicily) Italy. (Photo by Platania/Fotogramma/Ropi via ZUMA Press)





Replica of an old traditional Icelandic house from the 1800 with eruption of Iceland's Eyjafjallajökull volcano, 2013. (Photo by Ingólfur Bjargmundsson/Getty Images)