Every new volcanic eruption is a real-time opportunity to capture exactly what happens over
time and allows researchers to examine the resultant lava flows, explosive ash horizons and
other deposits. The spectacular Bárðarbunga, for instance, provided examples of the eruption
entering and diverting a modern river system that came down from the ice cap (e.g.
Figure 1b). This eruption also became the largest in Iceland for over 200 years with the lava
field covering 85 km², and an erupted volume of 1.4 km³ of new lava2
.
Older rock masses also provide clues of where ancient volcanic episodes occurred, their
timing and their relationship to surrounding rocks and Earth history. Modern systems
provide the key to understanding the past volcanic events, and geoscientists use the ancient
dissected systems to help them understand what happens within and beneath
volcanoes as they build volcanic constructions.