The Volcano That Changed The World Read Online Free PDF

change and the factors contributing to that change.
    Observing and i nterpreting the cores often made Mark feel like a voyeur, peeking into Mother Nature’s secrets and her past deeds. But as Mark often said to his students, “A fundamental principle of geology is that the past is the key to the present, and an ice core is a door to that past.”
    O f specific interest to Mark were volcanic eruptions, and now in particular, Santorini’s Thera eruption. It was ironic, thought Mark, that he was studying a volcano using ice. It was even more ironic that to understand events on the Mediterranean island of Crete, he was working on an ice core from a location in central Greenland called the “Crete site.” Drilling began on this particular core in 1972 and reached a depth of almost twenty-one thousand feet. Annual cycle counting of the Crete core indicated the oldest layer at the bottom was deposited in 1936 BCE. Thus, this core contained cycles from the time of the Thera eruption.
     
    The FSU email system had recently been upgraded. Since 1981, the NSF had expanded university Internet access, which was not commercialized until 1995. Although commercial Internet service providers were available, the FSU system was more extensive, allowing greater flexibility. Mark was an early user and took maximum advantage of both email and the Internet.
                  Alone in his office, Mark pounded back gourmet coffee from a freshly brewed pot. It was late and the coffee helped him focus. He was excitedly writing an email to a colleague, Dr. Brennan Hickenbottom, a fellow geologist and professor at the University of Birmingham in the United Kingdom, who was collaborating with Mark on the Thera volcano project. He could barely contain his enthusiasm as he described the results of his day’s work.
                  The cause of his excitement was a new discovery. Mark had just come from an adjacent laboratory where he’d finally been able to try out a new and sophisticated instrument called a “laser ablation inductively coupled plasma mass spectrometry” or LA-ICP-MS, what Mark simply called the “lap-miss.”
     
                  Earlier that evening, he had been in the ice core lab working on a sample from the Crete site in Greenland. The Thera eruption deposited ash on the ice sheet around 1600 BCE and could be identified in the ice core as a visible ash layer known to have an acidic chemistry. Mark was familiar with this particular core and with this particular layer of ice, having painstakingly removed a sample of glass shards from the Thera ash layer earlier in the day.
    The shards were tiny pieces of gas-bubble walls from volcanic magma broken during its explosive fragmentation. The shards of glass were small and light enough to stay suspended in the atmosphere until captured by a falling snowflake that landed on the Crete site those many years ago.
                  With the lap-miss, he was then able to analyze several single shards of the glass. For the first time, he identified the unique mix of trace elements in the glass that were in effect a unique signature or fingerprint of the Thera eruption. That meant he could now analyze ash deposits or layers from around the world and, with a high degree of confidence, determine whether they were associated with the Thera eruption. This was an important new scientific discovery—a breakthrough. He was excited to share his finding with Hickenbottom.
     
    Large droplets of rain slapped against his office window and a flash of lighting lit up the distant sky, but Mark barely noticed the storm as he typed.
     
                  Although it was well after midnight when he finished his message, Mark headed back downstairs to the ice core lab to retrieve other glass shard samples and to repeat his analysis. He was too excited to sleep. Besides, heading home required leaving the building, and going outside didn’t really appeal