Article 1 (Current Event)
For the first time in 33 years, the highest volcano in the Galapagos Islands, rising 1,710 metres above sea level, erupted in late May 2015. The huge eruption of Wolf Volcano in Isabela Island sent volcanic gases and ash about 15 kilometres into the sky and the lava that flowed from the volcano flowed through a fissure, leading to the sea. Seismologists from Ecuador’s Instituto Geofísico-Escuela Politécnica Nacional (IG) had detected rising activity in the caldera from June 12~16. According to Loff (2015), “The 7-kilometer (4 mile) wide caldera is nearly 700 meters deep.” With broad but gentle slopes that are like a ‘Polynesian Warrior’s Shield’, one lava flow tends to spread out across the previous flows of the shield volcano. The eruption raised fears of the unique ecosystem that was the inspiration for Charles Darwin’s theory of evolution would be harmed and that the local population of Chelonoidis becki tortoises and yellow iguanas would be under threat. The island also holds the world’s only population of pink iguanas but according to the Loff (2015), “Neither species has been endangered so far by the eruption” as the ash and lava flowed towards the east and southeast whereas the animals live towards the north and west of the summit.
Article 2 (Earthquakes)
On April 25th, 2015, a huge earthquake with a magnitude of 7.8 hit Nepal, destroying buildings/ houses in Kathmandu, harming World Heritage Sites and triggering violent avalanches near Mount Everest. The earthquake was the largest since Bihar earthquake in 1934, which measured 8.3 on the moment magnitude scale and killed around 10,000 people. Sitting on the boundary of two massive tectonic plates; the Into-Australian and Asian plates that collided to build the Himalayas, Nepal is prone to earthquakes. The earthquakes are a clear “manifestation of the ongoing convergence” between the two massive tectonic plates; Indo-Australian and Asian plates that have progressively built the Himalayas over the last 50 million years. (Sandiford, Rajendran, Morell, 2015). However, earthquakes are only one of the hazards that the communities living in the mountains face. Occasionally, there are floods and monsoonal landslides.
The earthquake occurred due to strain building up in the Earth’s crust which gave away and caused a catastrophe. In this case, the cause of the strain was the collision or convergence of the two plates (Indo-Australian and Asian). One of the reasons that made the results of the earthquake even more devastating was the fact that the focus of the earthquake was shallow; approximately 15 km below the surface at the quake’s epicentre and the ruptured part extended under an area with a dense population in Kathmandu.
Recently, a research team consisting of five Taiwanese researchers from the Institute of Earth Sciences at Academia Sinica, as well as Department of Geosciences and Institute of Oceanography at National Taiwan University made a new discovery about how mountain belts on the island were formed. According to Huang Tzu-ying, researchers have been debating whether the deformation takes place mainly in the upper crust or the basement rocks are also involved in the process. “Both conceptual models explain only part of the phenomena, and that the real mechanism remains uncertain given the difficulty in making direct deep-crust observations to test the theories. But by measuring surface waves derived from ambient seismic noises, we developed a hybrid model that has aspects of both theories. (Huang, 2015)”