2. Earthquake as a Hazard

Now, coming another important feature is the speed of onset like, if we consider a flood, it is a flash flood, it is very sudden without warning, very quick or is it a kind of slow process like in case of cyclone, we have much time to predict so, we have; we can prepare our self, we have better early warning system and we can take time but in case of earthquake, we do not have any time, it is very sudden.

The speed of onset refers to how quickly a hazard occurs after a warning or prediction. Some hazards like flash floods happen suddenly and unexpectedly, creating little to no time for preparedness. In contrast, events like cyclones can be predicted in advance, providing people with time to prepare. Earthquakes, however, occur without any warning, making them dangerous because people cannot take preemptive actions.

Imagine a race: a runner (the earthquake) that starts suddenly without any signal versus a marathon runner (the cyclone) who has an announcement of the race starting time. While the marathon runner can prepare, get into position, and gather supplies, the sprinter catches everyone off guard, creating panic.

And temporal spacing also very important; what time, when and it is happening, are they random, are they occurring in a cyclic process in a recurring process or they are one-time events, so these are important features when we are dealing with hazards.

Understanding the spatial and temporal aspects of hazards is crucial for effective disaster management. Spatial dispersion involves analyzing which areas are likely to be affected by a specific event, while temporal spacing focuses on when these events happen. Are they unpredictable or do they follow a pattern? This knowledge helps in planning and preparedness for potential hazards.

Think of planning a camping trip. If you know that rain occurs regularly in certain months (temporal pattern), and you have identified a flood-prone area (spatial dispersion), you can choose to avoid those months or areas, preparing yourself for a better experience.

In case of just for an example, maybe we can see that in case of earthquake; earthquake occurs along the boundaries of the tectonic plates of the earth crust. this is one hazard and when this is the source of the hazards and when this happen and this happens, we can see that these plates come in contact with each other and the pressure builds up an earthquake occurs.

Earthquakes happen primarily at the boundaries of tectonic plates. When these plates push against each other, pressure builds up. Once the pressure exceeds a certain limit, it results in an earthquake. This process illustrates that earthquakes are not randomly distributed but connected to the movement of the Earth's crust.

Imagine a tightly squeezed sponge. When you push on it and hold, it doesn’t change shape, but if you push too hard, you suddenly release a burst of water. Similarly, tectonic plates build up energy like the pressure in the sponge, and when released, it results in the sudden shaking we feel during an earthquake.

Now, this is just simply a physical event, this is you can see some of the distribution of the tectonic plates in some places and this hazard; this earthquake hazard, we have 3 processes; physical process that can trigger this hazard. One is that convergent boundaries; when two plates collide together this created the Himalayan mountain so, one way of the event of earthquake that can happen when two plates are colliding each other. Another was is the subductions; there is when one oceanic plate goes under the land plate and created this kind of earthquake. And another one is the divergent one, when two plates are moving apart, this can also cause earthquake. And this is we call divergent region.

There are three main types of tectonic plate boundaries associated with earthquakes: 1) Convergent boundaries, where plates collide, often resulting in powerful earthquakes and mountain formation like the Himalayas; 2) Subduction zones, where an oceanic plate is pushed under a land plate, also triggering significant earthquakes; and 3) Divergent boundaries, where plates move apart, which can also lead to earthquakes. Each type of boundary has different mechanisms that cause seismic activity.

Think of tectonic plates like giant, heavy books stacked on top of each other (convergent), where one book can slide under another (subduction), or books being pulled away from each other (divergent). The pressure from these movements can cause the books to suddenly shift, just like the earth shifts during an earthquake.

Now when we are talking about hazards, can we avoid hazard? No, historically hazards were there, it is there and it will remain. So, we cannot avoid hazard basically.

Hazards like earthquakes cannot be avoided; they are a natural part of the Earth’s geological processes. Despite advancements in prediction and preparedness, the occurrence of earthquakes is inevitable, which highlights the importance of planning and building resilient societies that can withstand such events.

Like the changing weather, where we can't stop rain or snow but can dress appropriately, we cannot prevent earthquakes but we can prepare ourselves by reinforcing buildings and having emergency plans.

Now, looking into the disaster; number of disasters from 1980’s to 2005, you can look as I told also before, it is the flood that is the most reported disastrous event. 35% of all disasters from 1980 to 2005 are flood disasters. Another one is also big share is the windstorm, earthquake is only 11%, an extreme temperature is 11%, so overall 90% of disasters are related to hydro-meteorological disasters.

From 1980 to 2005, floods were the most frequently reported disasters, accounting for 35% of all disaster events. Windstorms also made a significant contribution, while earthquakes represented only 11% of reported disasters. Understanding these statistics helps prioritize disaster preparedness and response activities based on historical trends.

It's like knowing the weather patterns in your region; if floods are common in spring, you would focus your emergency preparations more on that season instead of winters when they are less likely to occur.

Also, when we are looking into the loss of human life from 1980 to 2005, we can see that nearly 70% of loss of life are related to hydro-meteorological factors. So, hydro-meteorological disasters are very critical, particularly when we are looking into developing countries or underdeveloped countries.

Between 1980 and 2005, significant loss of life—about 70%—was attributed to hydro-meteorological disasters, such as floods or droughts. This trend is especially alarming in developing countries, where infrastructure and resources may be inadequate for handling such crises. Understanding this helps in focusing efforts where they are most needed.

Think about a village that relies solely on rain for crops; if floods hit, they can destroy the entire harvest, leading to hunger and loss of life. This is why understanding weather patterns and preparing for them is critical in vulnerable areas.

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