(CNN) Both eruptions swallowed homes and reminded everyone how ferocious nature can be. 
 
 But there are huge differences between Guatemala's Fuego volcano eruption, which has killed 62 people since Sunday, and Hawaii's recent Kilauea eruption, which hasn't killed anyone but keeps slowly wreaking havoc one month later 
 
 Here's why these eruptions are so different -- and why they have drastically different death tolls: 
 
 Lava vs. pyroclastic flow 
 
 Kilauea's primary mode of destruction is lava, but Fuego has unleashed pyroclastic flow -- a nasty mix of ash, rock and volcanic gases that can be much more dangerous than lava. 
 
 JUST WATCHED Deadly Guatemala volcano covers villages in ash Replay More Videos ... MUST WATCH Deadly Guatemala volcano covers villages in ash 01:49 
 
 In Guatemala, pyroclastic flow from Sunday's eruption topped 1,800 degrees Fahrenheit (about 1,000 degrees Celsius), CNN meteorologist Ivan Cabrera said. 
 
 "This eruption at Fuego was explosive, sending hot debris down the steep sides of the volcano to make the pyroclastic flows," said Erik W. Klemetti, associate professor of geosciences at Denison University. 
 
 He said pyroclastic flows can tumble down a volcano at hundreds of kilometers per hour -- way faster than what people and even cars could outrun. 
 
 By contrast, Kilauea produces lava (or sticky, molten rock) that typically creeps along at maybe hundreds of meters per hour -- not nearly as fast as devastating pyroclastic flow. 
 
 Pyroclastic flows are not like lava. PFs are rapid avalanches of hot gas & rock ranging from ash-sized (like sand) to boulders, + anything they pick up (like trees & cars). PFs are devastating & deadly. #VolcanodeFuego https://t.co/tABdt7bm3V — Dr Janine Krippner (@janinekrippner) June 4, 2018 
 
 Different communities 
 
 Kilauea is within Hawaiʻi Volcanoes National Park. Lava has destroyed dozens of homes and other structures in communities outside the park boundaries. 
 
 But the Fuego volcano erupted near densely populated areas. 
 
 "Villages are right on the foothills of the mountain," Cabrera said. "So they had no time (to escape)." 
 
 That meant unsuspecting villagers -- such as those in the community of El Rodeo -- were suddenly overwhelmed by ash, lava fragments and gases speeding toward them at 435 mph (700 kph). 
 
 Different long-term effects 
 
 In both the Kilauea and Fuego areas, "the land will be unusable for years," Klemetti said. 
 
 JUST WATCHED Lava torches Hawaii neighborhood Replay More Videos ... MUST WATCH Lava torches Hawaii neighborhood 01:12 
 
 But Guatemala faces a special danger that Hawaii doesn't. 
 
 "The bigger issue with pyroclastic flows is they can be turned into volcanic mudflows (lahars) when the loose debris mixes with rain/river waters," he said. "That is the new danger at Fuego right now." 

 The recent volcanic eruptions in Hawaii and Guatemala are a reminder that not all volcanoes are created equal: Some types pose a far greater hazard to life than others. 
 
 In the most recent eruption of Kilauea on the Big Island of Hawaii that began a month ago, most of the lava has oozed from fissures, spreading slowly enough that it is no threat to people — although hundreds of houses and other buildings in the lava’s path have been destroyed. 

 Deadly Volcanic Eruption Covers Guatemala in Ash and Debris 
 
 One of Guatemala's most infamous volcanoes is living up to its name. The Volcan de Fuego, Spanish for fire volcano, erupted overnight. Video emerged showing rapidly moving ash plumes, making it stand in stark contrast to the images of lava oozing slowly from Hawaii's Kilauea over the past month. 
 
 The different eruptions in part explain why more than two dozen people were killed in the wake of Fuego's eruption, while most damage in Hawaii has been the slow destruction of physical structures over the past month. 
 
 There's a scientific reason for that. 
 
 Whereas Kilauea, a shield volcano, is characterized by large globs of slow-moving lava inching out of fissures, Fuego, a stratovolcano, is prone to spewing fast-moving flows of ash, lava, and mud. 
 
 They're different eruption styles are born from the volcanoes' unique underlying geology, says Concord University volcanologist Janine Krippner. 
 
 “The magma itself is quite different,” she says. “The magma at Kilauea is quite runny, which means the gasses can easily escape. At Fuego, the magma is stickier and more viscous.” 
 
 That sticky magma traps enough air to build up pressure until an explosive eruption occurs. In rare instances, it can form a new crater, but the eruption at Fuego came from its existing main crater. 
 
 The worst of the volcano's impacts are chain reactions following the fiery eruption. 
 
 After an eruption explodes from Fuego's crater, it deposits loose rock and volcanic debris onto the volcano's slopes. Pyroclastic flows form when the ash and rocks, some as large as boulders, form hot, fast avalanches that rapidly descend. 
 
 “They're extremely hot and extremely lethal,” says Krippner. 
 
 After these pyroclastic flows disperse, the loose rock stays behind. Because much of Guatemala is tropical, it experiences frequent and heavy rainfall. When this mixes with the volcanic debris, rainfall can form dangerous mudflows called lahars. With minimal rainfall, the lahars move like wet concrete, but after intense rains, they can turn into watery flash floods that inundate valleys. 
 
 The region surrounding the volcano is also experiencing poor air quality, a common impact of volcanic eruptions. Inhaling volcanic ash can lead to respiratory issues, and experts advise staying indoors. 
 
 Fuego is one of three stratovolcanoes in the region. Though they all sit over a geologically active area, there's no evidence that an eruption from one volcano could trigger an eruption in one of the others, notes Krippner.
– The eruptions of Hawaii’s Kilauea volcano and Guatemala’s Fuego volcano are both devastating but in very different ways, reports the New York Times. The Kilauea eruption has been a slow-motion disaster, steadily destroying homes for a month but presenting little threat to people, while the Fuego eruption has been faster and fiercer, killing more than 100 thus far. Scientists say the volcanos have different underlying geology and magma viscosity. "The magma at Kilauea is quite runny, which means the gasses can easily escape," a volcanologist tells National Geographic. "At Fuego, the magma is stickier and more viscous." Fuego is belching what's called a "pyroclastic flow," a fast-moving noxious cocktail of rock and gas with temperatures topping 1,800 degrees Fahrenheit, per CNN. By contrast, Kilauea’s lava flow is moving so slowly that people can easily walk away from it. "Lava flows rarely kill people," one volcano expert tells the Times, but "you will not survive a pyroclastic flow." The volcanos’ proximity to population centers has also made a difference: Kilauea is located in a national park, while Fuego is near densely populated areas that were quickly overtaken by ash and gas moving at more than 400 mph. Both regions will be uninhabitable for years, but according to one analyst, Fuego poses the additional challenge of volcanic mudflows that occur "when the loose debris mixes with rain/river waters."