Summary on Earthquakes Volcanoes and Landslides

15

3750

It covers the sea beds and is the foundation of land masses. Tectonic plate shifting along fault lines is the primary cause of major earthquakes. However this is not just the sole reason for earthquakes. Localised low intensity and low impact earthquakes also occur frequently everyday at different parts of the world. They are due to the shifting of underlying layer of soil, and are confined only to small localities in cities, town or rural area. Lisbon, 1755: The Lisbon Earthquake: The Lisbon earthquake in the country of Portugal back in the 1st of November 1755 was one of the most ghastly natural calamities in the memory of mankind. Nothing every of such gigantic destructive scale had ever occurred in the near recallable future, swallowing everything from a huge civilisation, to thousands of people, human constructions etc. The Lisbon earthquake due to its sheer magnitude of destruction is till date studied by geologists, seismologists, construction firms and earthquake experts. The natural disaster on the 1st of November 1755 in Lisbon was a combination of two natural disasters: A series of high and medium intensity earthquakes followed by an equally devastating Tsunami, due to the aftershock of the earthquake. The date was November 1st 1755 at 9:30 am, one of the most scared days in the Roman calendar (All Saints’ Day), thousands of devotees and followers had gathered in the innumerable streets and lanes of Lisbon crowding near Cathedrals or flocking towards the smaller churches. The day was crisp and clear and the priest had just begun chanting “Gaudeamus omnes in Domino, diem festum…” when the cathedrals and churches started to sway and lurch from side to side. The bronze bells began to ring madly and candles toppled from their stands and fell over. Within seconds from the initial ushering of the tremor, it gathered intensity and magnitude, tossing buildings down like match boxes and dislodging large chunks of masonry that fell on fearful worshippers crushing them to their death. The second larger shock came a few seconds later and caused even more damage compared to the first one, razing damaged construction and building to dust, killing thousands. After 90 minutes from the last major shock, three devastating Tsunamis struck the coast of Lisbon one after the other wiping out human settlement along the coast line and leaving nothing but indistinguishable ruins and mangled remains of construction debris and human bodies washed up on the shores. The extensive damage caused by the earthquake triggered a massive fire outbreak in the entire city, initiated by toppled candles and broken hearths, that set flame to the highly combustible wooden buildings. Soon the entire city was engulfed in the violent lashings of flame, charring to death thousands of people and leaving nothing but roasted remains of human property and burnt dead bodies. This was the horrific natural calamity in Lisbon two and a half centuries ago that killed tens of thousands of people and scarred the entire city mercilessly with irreversible damage that took centuries to rebuild. San Francisco, 1906: The San Francisco Earthquake: San Francisco was no stranger to destructive earthquakes and fires. It had burnt down 6 times during the years of gold rush in the years 1849 – 1851. This was because most of the building were made of flimsy