In sync with this oscillating gas chemistry, emerging data show, the lava lake’s surface experiences a rhythmic 2- to 3-meter rise and fall. The proportion of different gases changed in a pattern that repeated every 10 to 18 minutes. Several years ago, Erebus watchers stumbled upon subtle cyclic variations in the gases emanating from the lava lake. The bubbles’ size and content offer valuable clues to their origin - and the volcano’s stability. Effectively Erebus’ blood gases, these volatile chemicals rocket up from below Earth’s crust. To understand it all, Kyle and his colleagues focus on water vapor and other gases that bubble up through the magma. Its conditions affect whether Erebus just exhales streams of carbon-rich gas or snorts out the occasional car-sized lava bomb. With an ever evolving battery of physical and chemical tests, these Erebus observers have been probing the volcano’s dynamic plumbing system beneath the magma chamber. That’s why Kyle - one of the most seasoned of Erebus watchers - has trekked to Antarctica annually for four decades.Īlong with shifting teams of other researchers, Kyle collects the volcano’s vital signs in an ongoing effort to gain clues to its inner workings - clues that might help scientists understand volcanoes elsewhere on the planet. And ironically, Kyle says, Erebus is perhaps the most accessible of such volcanoes - with the best logistical support thanks to transportation and other resources available through NSF at McMurdo. Only a few volcanoes, like Erebus, have lava lakes that have been open to the sky for decades, making them prime spots for the study of volcano behavior. In most volcanoes, magma hides beneath a rocky cap. The lava in the lake rises up from inside a magma chamber somewhere deep below the primary crater on Erebus. The magma chamber is the heart of a volcano it controls and governs all eruptions. “This lava lake is a window into the volcano and its magma chamber,” says volcanologist Philip Kyle of New Mexico Tech in Socorro. Few, however, have scaled the nearly 3,800-meter summit to peer into its churning pool of molten rock - a lake of lava roiling at roughly 1,000° Celsius. Some 1,300 summer residents at the National Science Foundation’s McMurdo research station 35 kilometers away can revel in the picture-postcard backdrop that Erebus offers. This ice-covered cone belongs to a small chain of otherwise dormant peaks that make up Ross Island. As it rises through the crust it can change composition before finally reaching the upper volcano system (inset) and migrating to the magma chamber and lava lake, located 2 to 4 kilometers above sea level. THE RISE OF MAGMA | Molten rock begins its upward journey deep inside the mantle. Oppenheimerįeldspar crystals mined from lava bombs contain clues to the composition of the volcano’s magma. Scientists point a variety of instruments at the lava lake to measure its appearance, gas emissions and sounds. Zandomeneghi et al/Journal of Geophysical Research A topographical map shows 12 detonation sites and the locations of seismometers that record the shock waves generated by the explosions, which give clues to the density of materials within the volcano and aid in mapping its inner workings. SEISMIC EVIDENCE Scientists drill in order to plant an explosive charge. Most lava bombs contain crystallized feldspar. Nelia Dunbar pokes a lava bomb freshly catapulted from the lake. From the rim, scientists can watch - and listen to - lava that has risen from the magma chamber. Feliciano Ridvan EFE/ShutterStockĮrebus’ lava lake is open to the sky and easy to observe. From the rim they observe the lava lake below, measure its emissions and probe Erebus’ plumbing system. Researchers travel from McMurdo Station to a research base near the top of the volcano. MOUNTAINTOP LAB | Mount Erebus, Earth’s southernmost active volcano and one of four moutains that form Ross Island, rises from Antarctica’s Ross Sea. Wind-blown clouds of steam rise year-round from a lava lake atop Mount Erebus, the planet’s southernmost active volcano.Įrebus’ lava lake churns beneath a cloud of gas and water vapor, yielding clues to the volcano’s inner workings. MCMURDO STATION, ANTARCTICA - Even when the December sun beats down 24 hours a day, most of Antarctica remains cold, if not brutally frigid.
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