tailed off during the 6th millennium. Global water levels had risen by about 60 metres due to deglaciation of ice masses since the end of the Last Ice Age. Accelerated rises in sea level rise, called meltwater pulses, occurred three times during the EHSLR. The last one, Meltwater Pulse 1C, which peaked c. 6000 BC, produced a rise of 6.5 metres in only 140 years. It is believed that the cause was a major ice sheet collapse in Antarctica. Approximately 8,000 years ago (c. 6000 BC), a massive volcanic landslide off Mount Etna, Sicily, caused a megatsunami that devastated the eastern Mediterranean coastline on the continents of Asia, Africa and Europe. In South America, a large eruption occurred at Cueros de Purulla c. 5870 BC, forming a buoyant cloud and depositing the Cerro Paranilla Ash in the Calchaquí Valleys. A cataclysmic volcanic eruption occurred c. 5700 BC in Oregon when high Mount Mazama created Crater Lake as the resulting caldera filled with water. Another major eruption occurred c. 5550 BC on Mount Takahe, Antarctica, possibly creating an ozone hole in the region. The carbon-14 content in tree rings created c. 5480 BC indicates an abnormal level of solar activity. Astronomy and calendars The epoch of the Byzantine calendar, used in the Byzantine Empire and many Christian Orthodox countries, is equivalent to 1 September 5509 BC on the Julian proleptic calendar (see image right). The 6th millennium BC falls entirely within the Astrological Age of Gemini (c. 6450 BC to c. 4300 BC) according to some astrologers. References -94