Certainly, Jurassic World: Fallen Kingdom is an entertaining movie, and one filled with a surprising number of references to the US President. Saying that, we regret to inform you that the spectacular volcanic eruption that kicks off the events of the movie – among other things – is broken as hell. Spoilers ahead.
Right. Let’s get this out of the way before the angry emails flood in: I love volcanoes, even if they can be destructive or deadly sometimes. At the same time, I like squeezing out as much science as I can out of pop culture, from Star Wars to Jurassic World.
This isn’t a rant about the Fallen Kingdom, especially as the volcanic eruption sequence looked amazing. The stratovolcano, which looks a bit like Mount Fuji, Mount St. Helens, Volcan de Fuego and many others, was, however, weird beyond belief. Volcanic eruptions producing pyroclastic flows and surges are terrifying and deadly enough as it is, but it looks like the creators of the movie just thought give me all of the volcano stuff in one go.
There’s a lot to rant about this particular Frankenvolcano over on Isla Nublar, a few hundred kilometers west of Costa Rica. From this point onwards, there are plenty of spoilers so avert your eyes if you’ve yet to see it unfold yourselves.
At the start of the movie, a bizarrely expositional BBC News broadcast informs us that the island’s volcano – Mount Sibo – which is currently erupting a small plume of ash, is set to cause an “extinction level event” and kill all the dinosaurs and pterosaurs on the island. Hence, the rescue attempt.
Let’s go through it, step by step, with the help of volcanologist Nathan Magnall of Lancaster University.
When Pratt et al. arrive on Isla Nublar, the volcano is already flinging out the occasional lava bomb, very sizable chunks of freshly cooled lava. Then, as shenanigans ensue, there’s a bit of a double cross involving the mercenaries and Blue, the super-smart “Velociraptor”, some tranquilizer darts, and Pratt falls to the ground, unconscious. Meanwhile, Bryce Dallas Howard’s character is trapped inside a building nearby.
With impeccable dramatic timing, the volcano then goes apeshit. Pyroclastic density currents (PDCs), those superheated mixtures of ash, gas, lava blebs, and debris, form through small summit blasts. Fissures form with incredible speed, covering what appears to be several kilometers instantaneously on the flanks of Mount Sibo, spewing lava all over the place.
Lava oozes out everywhere, and moves around at a fairly rapid pace, pouring through the ceiling of the building and at one point briefly landing on a predatory dinosaur’s head, which merely shakes it off. Elsewhere, Pratt, still weak from the tranquilizer, awkwardly rolls his way to safety.
Lava, by the way, is incredibly dense. It’s molten rock, so if you fell into it, you wouldn’t even really sink. If it lands on you – even if you’re a huge theropod dinosaur – it would probably crush the top of your skull, much like it smashed the leg of the only person injured in Kilauea by flying lava to date.
You couldn’t just shake it off either: it would melt into you, leatherize your skin, and eat way at your innards. That dino wouldn't have certainly shuffled off its mortal coil, but that’s just the start.
“Obviously, the eruption sequence was a bit unusual,” Magnall told IFLScience. “Simultaneous eruptions of lava and PDCs would be pretty weird.”
Yes, you can get explosive activity alongside lava flows – and volcanoes that can switch between the two eruption types, like Mount Etna – but not on this scale at the same time. This volcano was part-Kilauea with its extensive lava flows and part-Fuego with its PDCs. You’d not get both like this at the same time.
Fissures can form quickly, but not like that: If a volcano was cracking open this quickly, the contents of its magma reservoir would burst out the side of the volcano, much like it did during the 1980 disaster at Mount St. Helens.
“I would also take issue with the lava advance rate,” Magnall added. Pahoehoe lava, the fluid, gloopy flow seen in the film, is common for volcanic systems with low-silica magma, like Kilauea. The fastest flows on Hawaii have been seen moving at no more than 18.2 meters (60 feet) per hour, which is above average, but way slower than that in the movie.
In fact, the movie’s lava is flowing so fast that it must have a very low silica content, and silica gives magma/lava its viscosity. Magma with a low viscosity cannot trap gas very well, so if it’s kept in an undisturbed magma reservoir, it won’t trigger an explosive eruption because the gas can easily escape.
So quite how Mount Sibo kept producing huge explosions is beyond me.
The volcano also explodes in bits. Instead of one huge summit blast, the mountain’s heights are peppered with explosions, which tumble down into the valleys and form pyroclastic density currents within minutes of each other – again, each happening as the drama unfolding below required.
Magnall mentioned that multiple PDCs is fine; after all, that’s what’s been happening at Fuego. Having so many individual PDCs, formed by flank explosions near the summit, however, is weird.
“It all struck me as like putting a volcano on fast forward,” he concluded.
Then, as the escape really kicks off, the volcano goes Super Saiyan, triggering a colossal PDC, leading to Pratt and company – along with every dinosaur under the Sun – to somehow outrun it and jump off a very high cliff into the sea. We’ve already covered this bit extensively, by asking a volcanologist and a paleontologist if human or dinosaur could outrun or survive a pyroclastic flow or the gassier equivalent, a surge.
Finally, as our heroes escape, they turn back from their boat-based sanctuary and see a Brachiosaurus look back at them. As it became surrounded by lava and, as the lava entered the sea, volcanic haze (laze), it reared up on its hind legs, let out a melancholic roar, and then faded away.
Laze is a real thing. You’ve probably seen images of it emerging from the sea as lava flash-boils it over in Kapoho Bay on Hawaii’s Big Island. Breathing it in is pretty bad for anyone with respiratory conditions, but in this case, the impossible lava flow probably melted the poor gentle giant before it could die of lacerated lungs.
Sorry Mount Sibo, but you make about as much sense as a chocolate teapot.