It is worth pondering how an artist living in the time of the European Renaissance deduced so much about Earth’s history and deep time in the face of skepticism from contemporary scholars and religious orthodoxy. A possible explanation is the power of keen observation and attention to fine detail. Those artists who work with and portray rocks, fossils, and landscapes grapple with the same things as geologists, and both begin by carefully observing the natural world. Through observations, artists find inspiration and beauty. In contrast, geologists rely on observations to understand what has happened in the past, working from the assumption that the present is the key to the past. Tony Foster weaves geologists’ understanding of time into his work so that each painting portrays powerful geologic events, such as the movement of one tectonic plate against another along the San Andreas fault or the uplift of fossils to the pinnacles of the Himalayan Mountains. His work draws the viewer in to contemplate not only Earth’s beauty but also its past and the processes that shape it over time, resulting in a remarkable experience when viewing his art. Like geologists, Tony is fascinated with deep time, but as an artist, he reveals its complexity in images he painstakingly creates during expeditions to remote landscapes. His paintings, in turn, inspire awe and curiosity in his artistry and Earth’s extraordinary history. Catastrophic Geological Change Sir Stephen Sparks CBE FRS PROFESSOR OF GEOLOGY IN THE SCHOOL OF EARTH SCIENCES UNIVERSITY OF BRISTOL Geological processes create landscapes and some of these processes are exceedingly slow. For long periods of time nothing very much happens or the changes are impercepti- ble. On the sea floor across much of the World’s ocean, for example, only a few millimetres of mud accumulate every thousand years, while mountains may wear down at similar very slow rates. However, some processes are catastrophic and make huge changes to the landscape in the twinkling of an eye. Volcanic eruptions are a dramatic example. In 1995, the Soufrière Hills Volcano in Montserrat in the eastern Caribbean started a major eruption that eventually lasted 15 years and erupted over a cubic kilometre of magma (molten rock). The one kilometre wide crater is now filled with a new mass of lava 400 metres high. A consequence of the eruption was that several thousand people had to be evacuated from Montserrat and many of them never returned home. Tony’s painting of the volcano in eruption took place from a place called St. George’s Hill about 3 kilometres to the north east of the volcano on Friday, 6th December 1996. The scene looks ominous and menacing. The two moun- tains were formed by eruptions about 70,000 (the higher background peak called Chances Peak) and 180,000 years ago (the nearer Gages hill). The active volcano is behind them. Much of the two peaks have been stripped of the normally lush green tropical vegetation by the highly acid and corrosive gas emissions to become barren and forlorn. The grey swirling cloud is not meteorological but volcanic ash plumes that have been emitted by the erupting volcano and are drifting out to sea, blown eastward by the wind. Much of the ash at this time was formed by a growing mound of glowing lava called a dome which was very unstable and so falls of hot (850oC) rock were continu- ously falling off the dome. Ash is fine-grained volcanic particles (rock dust) formed spontaneously by disintegra- tion of hot rocks tumbling down the steep slopes of the dome. The painting was composed fairly early in the eruption and the full power of the volcano had not yet been unleashed. On the previous night, however, 150 small earthquakes had been recorded on the network of seismometers around the volcano installed to give early warning of large volcanic eruptions. The earthquakes were due to sticky, very viscous magma rising along conduits from a huge magma chamber about 5 kilometres deep beneath the volcano. The under- ground flow of magma fractured the rocks surrounding the magma conduit and caused the earthquakes. On this day the scientists in the Montserrat Volcano Observatory had given an orange alert and the population living near St. George’s Hill was evacuated that evening. In hindsight, the eruptions in 1996 were quite small. During 1997, much larger eruptions took place as the lava dome increased in size. One of the most dangerous phenomena occurred when a piece of the dome broke off to form large hot avalanches called pyroclastic flows which could move at tens of kilometres per hour. Such flows occurred repeatedly and buried the capital town of Plymouth on the east coast just as the eruptions of Vesuvius had buried the Roman town of Pompei in AD 79. On 25th June 1997 a huge pyroclastic flow on the south side of the volcano killed 20 in the fertile fields surrounding the volcano which can be seen in the painting. On 26th December 1997 an even larger and very violent flow moving at an incredible 300 kilometres per hour completely destroyed the village of St. Patrick’s on the east coast. Fortunately none of the several hundred people from the village lost their life because they had been evacuated. The eruption changed the landscape in the north of the island profoundly and the effects of the eruption will last decades. Even now, although the eruption has stopped, the volcano typically has several earthquakes a day and the ground is still rising due to hot pressurised magma below. Hot gas at temperatures of several hundreds centigrade is discharging from the new lava mountain. The rain forest will have to re-establish itself. Now only about 4,000 people live on the island compared to 12,000 before the eruption and there is still the concern that there could be further eruptions soon. 97
