Iceland's Bardarbunga volcano has now emitted the most lava of any volcano in that geologically active country since at least 1947, and continues with no sign of stopping. The volcano is also emitting clouds of toxic sulfur dioxide gases, which have made it all the way to Europe at times, thanks to northwesterly winds.

The eruption is taking place in an old lava field known as Holuhraun, and according to National Geographic, the volcano has now vaulted so much molten rock to the surface that it would fill at least 740 Empire State Buildings. The total area of lava spewed out by the volcano is 64.6 square kilometers as of Oct. 28, which works out to about 25 square miles.

According to Nature magazine, the volcano has emitted more sulfur dioxide gases since the eruption began in August than Europe produces in an entire year through industrial activities.

Sulfur dioxide emissions have been far higher, however, in past eruptions of volcanoes in Iceland.

Lava flowing from the Bardarbunga volcano in Iceland on Sept. 2, 2014 Image: Arctic-Images/Corbis

There are no signs that the volcano is about to stop erupting, either. Just on Tuesday, about 80 earthquakes occurred in the vicinity of the volcano, including two that were stronger than magnitude 5. And over the weekend there were 200 earthquakes, which were a sign of continued movement of molten rock, or magma, beneath the surface, and continued settling of the main Bardarbunga caldera.

A caldera is a crater-like land feature that is usually formed from an explosive volcanic eruption, and Bardarbunga is a type of volcano, known as a stratovolcano, that is prone to developing calderas because of successive explosive and more muted eruptions.

According to the latest scientific update on the volcano, since the start of the seismic activity in August, the caldera has sunk by about 40 meters, or 131 feet. These measurements come from GPS instruments that scientists have installed for volcano monitoring. Magma is moving from the caldera, through a dike underground until it emerges in spectacular fashion in the Holuhraun lava field.

The Icelandic Meteorological Office has been providing two-day "gas dispersion" forecasts for the sulfur dioxide emissions emanating from the Holuhraun eruptive site. People in the path of the gases have been advised to stay indoors, and call doctors if they experience health problems. Such gases have been known to cause problems for people with respiratory ailments, in particular.

Scientists monitoring the volcano continue to say that three scenarios are equally likely for how the eruption may play out in the near future. The first is that the eruption and sinking of the caldera both come to a stop. One might call this the easy way out option.

An image from NASA's Landsat Satellite, showing the lava emerging from a fissure in the Holuhran lava field on Oct. 24, 2014. Image: NASA

The second scenario is far more problematic, involving continued sinking of the caldera that would strengthen the eruption of magma on the Holuhraun lava field. "In this situation, it is likely that the eruptive fissure would lengthen southwards under Dyngjujokull," the Oct. 27 scientific update states, referring to the name of a glacier that lies atop the caldera. This scenario could result in a glacial outburst flood and possible an ash-producing eruption.

In other words, this is not the preferred scenario for the people of Iceland, and international air travelers whose trans-Atlantic flights could be disrupted by ash clouds.

And the third scenario is that continued "large-scale subsidence of the caldera occurs," resulting in an eruption at the edge of the caldera, rather than the lava field. This could melt a large amount of ice, causing a flood and maybe an "ash fall."

By spewing ash high into the atmosphere, a major eruption could disrupt international air travel and potentially even cool the planet's climate for several months to a couple of years. In the past, massive eruptions from Iceland's volcanoes have affected the entire globe by cooling the planet, such as the eruption of the Laki volcano in 1783.

However, so far, there have been few signs that such a massive, explosive eruption is imminent.