The Yellowstone ranger's truck windshield is spattered with dirt when shown from inside the cab looking out, but is clean when shown from the outside looking in.
The rock-climbing team are show at middle distance climbing up a roughly 45 degree slope of very dark rock, but then close up has them on almost vertical light rock.
At a university, a bell rings to end the class. This is only typical of classes in K-12 schools in the U.S. College courses vary in lengths of time usually from 30 minutes to 2 hours, & thus, not all classes begin or end at arbitrary times.
In the opening scene, Jeff's first line is, "Tell me again why we're sitting on top of this rock called Trollsvatn?" The Icelandic word "vatn" means "lake". Since the volcano they are surveying is a mountain, it would be more likely to be named "Trollsfell" ("fell" means "hill" or "mountain", as in the volcano Eldfell). However, most Icelandic volcanoes have individual names, often taken from the nearest landform, be it glacier, headland or other formation. There is one volcanic area in Iceland with the word "vatn" in its name, but it refers to a volcano with its magma chamber and vent under a series of frozen-over lakes at the edge of a glacier.
Peter Shepherd tells Brianna Chapman she has to buy her own plane ticket if she wants to travel to Iceland with his team. The team is flying on a chartered jet which does not require an individual to purchase a ticket. This would only be needed if they were traveling on a commercial flight.
The submarines are launching nuclear armed torpedoes which have been part of various nations' arsenals since the 1950s. However, the detonations often appear to be conventional. The submarines are far too close to the explosions to survive an underwater nuclear detonation of even few kilotons.
The submarine Kai is on is the U.S.S. Reprisal. All modern U.S. nuclear submarines are named for U.S. cities, states, or important people in U.S. naval history.
When the team boards the Blackhawk after escaping the eruption in Iceland, it is clearly not the inside of a helicopter.
On board the British submarine, a flag is painted on the periscope housing. This flag, red background with crossed swords a lion and a crown is that used to represent the British Army - who do not operate submarines.
The Russian flags on the uniforms of the Russian submarine crew's uniforms are upside down.
In the lava tube, there are conveniently installed electric lights in the ceiling.
It makes no sense that magma would drip from above into the lava tube. Elsewhere on the same level, they find a magma chamber that is rising. The magma would spread into the tunnels, including the lava tube, before it could get into an area above the lava tube. The lava tube would have been filled with magma before any other magma could break through the ceiling into it.
Not once but twice the ETA for helicopter rescue extraction is five minutes, which is ridiculously soon. On the second extraction, the helicopter arrives in one minute. It also lands closer to the eruption than to the evacuees, forcing them to walk closer to the eruption.
While giving his lecture, Peter Shepherd says the video was shot at Hualalai. However, Hualalai, a Hawaiian volcano, has not erupted since 1801.
A voiceover from a news broadcast tells of the city of Rome being threatened by eruptions of Mount Vesuvius and Mount Etna. Vesuvius is in the vicinity of Naples, over 100 miles from Rome; Etna is on the island of Sicily, over 200 miles from Rome and separated from the Italian mainland by the Straits of Messina. Neither mountain is in a position to threaten Rome, even in the case of a severe eruption. The only possible reason for mentioning them is 1: they're volcanoes and 2: they're in Italy.
The models of Trollvatn and Grímsvötn are shown as steep-sided stratovolcanoes or cinder cones. Icelandic volcanoes such as Grímsvötn are gently-sloping shield-type volcanoes.
Grímsvötn itself lies under a huge glacier, the Vatnajökull icecap, not with a steep cone rising up out of it.
While our group of heroes are preparing to board the plane the boom mic is visible in the reflection in the side window of the van window.
When the heroes are on their way to Iceland in the plane, two out of four of these supposed graduate students don't understand the volcanic significance of Iceland; that seems highly unlikely.
Shepherd tells Brianna that the volcano they're on, Trollsvatn, is where Jules Verne's fictional explorers went underground in "Journey to the Center of the Earth". It's not. The passage Verne used was in a volcano under the glacier Snaefellsjokull.