The earth where we humans live is an extremely complex "giant system". The surface of the earth is composed of four major circles, including lithosphere, , atmospheric circle, biosphere and hydrosphere, and this "giant system" of the earth is in constant motion, which will produce many geographical events. If these natural events that are dominated by natural reasons cause losses to human society, we call them natural disasters .
Why do Indonesia suffer repeated tsunami attacks?
Natural disasters are complex, potential, mass, periodic, sudden and multi-causal. According to the causes of natural disasters, they can be divided into four categories, namely meteorological disasters, geological and geomorphic disasters, biological disasters and marine disasters. Among them, marine disasters refer to disaster events that occur on the ocean or coast, mainly including disastrous waves, sea ice, red tides, tsunamis and storm surges. The tsunami is the most harmful natural disaster among marine disasters. Recently, our Southeast Asian neighbor, Indonesia , suffered a tsunami attack.
2011 Japan tsunami
News information: On September 28, 2018, a strong earthquake and tsunami occurred in , Central Sulawesi Province, Indonesia, , the disaster caused more than 2,000 deaths, more than 2,500 serious injuries, and nearly 70,000 houses were damaged, and tens of thousands were forced to evacuate their homes. This is the worst natural disaster in Indonesia in the past five years.
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 Why do Southeast Asia Indonesia repeatedly attacked by tsunamis?
Comparison of some places in the 2004 Indian Ocean tsunami comparison diagram
Tsunami disaster is a kind of destructive wave, usually caused by submarine earthquakes, submarine landslides, and volcanic eruptions. Among them, submarine earthquake is the main cause of tsunami , and tsunami is a secondary disaster. The tsunami is extremely fast, usually reaching 700 to 800 kilometers per hour, and can cross the ocean within a few hours. The energy loss during the transmission process is very small. In the ocean, the tsunami waves are less than 1 meter high. However, once they advance to the nearshore and shallow waters, the wave height increases sharply, and can even reach dozens of meters, causing great harm.
Distribution map of six major plates and volcanic seismic zones
Therefore, we can find that the occurrence of two tsunami disasters in Indonesia is caused by earthquakes, that is, due to the frequent earthquake disasters in Indonesia, it is more likely to induce tsunami disasters. From the perspective of plate tectonic theory , Indonesia is located at the boundary of extinction of plate , the Asian and European plates and the Pacific plates. The plate collision and squeeze, and many volcanic earthquakes are at the intersection of the Pacific Ring Seismic Zone and the Mediterranean Sea- Himalayan earthquake zone . It is the most frequent earthquake disasters in the world, with more than thousands of earthquakes every year.
Global Centennial Earthquake Data Visualization
Secondly, tsunami disaster is a kind of marine disaster, mainly destruction of near-shore areas. Indonesia is the largest archipelago in the world, with more than 17,000 islands and a long coastline. Moreover, Indonesia has a large population, with a total population of 264 million in the country, and a large population is distributed in the coastal areas of various islands. The archipelago has a large population and is mostly distributed in coastal areas, which is one of the reasons for the huge losses caused by the tsunami disaster in Indonesia .
004 tsunami arrival time diagram of the 2004 Indian Ocean tsunami arrival
Since the major tsunami disaster occurred in the Indian Ocean in 2004, the world has established a global tsunami warning system, but for countries like Indonesia that are very close to the place where the tsunami is generated, it is difficult to have a reaction time.So we need to have our own prevention. Generally speaking, the propagation speed of seismic waves is faster than that of tsunamis, and there may be a time difference of several minutes to dozens of minutes. If you are at the beach and feel an earthquake, you should transfer immediately. In addition, if you observe tides suddenly abnormally fluctuating and falling, such as the sea water recedes rapidly, you should leave the coast immediately at this time. It is very likely that the tsunami is about to come .
Tsunami attack
