An earthquake is a geological phenomenon that occurs when there is a sudden release of energy in the earth’s crust. This can cause vibrations or ground movements that are felt on the surface of the earth. Let’s discuss some important points related to earthquakes:
Causes of Earthquakes
Earthquakes are generally caused by the movement of tectonic plates in the earth’s crust. The earth’s crust is divided into several plates that move slowly over time. When these plates interact with each other, such as moving away from each other or moving towards each other, pressure and friction can accumulate. When this pressure exceeds the resistance limit of the rock material, energy is released in the form of an earthquake.
Characteristics of an Earthquake
Earthquakes have several identifiable characteristics. Following are some general characteristics of earthquakes:
Vibrations or Shaking: One of the most obvious characteristics of an earthquake is the vibrations or shaking felt on the surface of the earth. These vibrations can last for a short time or longer depending on the size and depth of the earthquake.
Echoing or Rumbling Sounds: Some earthquakes, especially those with large magnitudes, can be followed by echoing or rumbling sounds that sound like a train or thunder.
Aftershock: After a major earthquake occurs, a series of smaller earthquakes can follow. These small earthquakes are called aftershocks. Aftershocks can occur within hours or even weeks after the main earthquake.
Land Surface Changes: Earthquakes can cause changes to the land surface. This could be a crack in the ground, a landslide, or even vertical movement on the surface, which can affect structures and buildings.
Water Source Disruption: Earthquakes can affect water sources, such as wells or springs. This disturbance can take the form of an increase, decrease, or even temporary drying of the water source.
Displacement of Objects: Earthquakes can cause objects on the surface to shift, such as household furniture or items in stores. This shift can be a clear sign of an earthquake.
Effects of Waves in Water: Earthquakes under the sea can cause changes in waves on the surface of the water, which can lead to tsunamis.
Power and Communications Disruptions: Earthquakes can often result in power outages and damage to communications infrastructure, such as telephone and internet networks.
Lowering or Rising of the Earth’s Surface: Earthquakes can cause lowering or rising of the earth’s surface in some areas. This process is known as deformation of the earth’s crust.
Seismograph Report: The scientific hallmark of an earthquake is the record produced by a seismograph. Seismographs record seismic wave vibrations that occur during an earthquake.
Recognizing these characteristics can help identify whether an earthquake has occurred and how serious its impact will be. If you feel shaking or have other signs, it is important to follow proper safety measures, such as protecting yourself and seeking shelter if necessary.
Epicenter and Hypocenter:
Epicenter is the point on the earth’s surface that is located directly above the hypocenter, namely the point in the earth where the release of earthquake energy occurs. The closer the epicenter is to the surface, the stronger the earthquake vibrations will feel.
Earthquake Scale
Earthquakes are measured on the Richter scale or moment magnitude scale (Mw). The Richter scale measures earthquake energy based on wave amplitude, while the magnitude scale moment measures the total energy released by an earthquake. The Richter scale is generally no longer widely used, and the magnitude scale moment more accurate and can measure larger earthquakes.
Seismology
The science that studies earthquakes and their related phenomena is called “seismology”. Seismology is a branch of geology that focuses on the investigation and understanding of earthquakes, earth vibrations, and the movement of seismic waves within the earth and on the surface. Seismology covers various aspects, including the origin, causes, movement, and impact of earthquakes.
Seismological scientists, called “seismologists,” use a variety of methods and tools to collect data about earthquakes. Some important areas in seismology include:
Seismography: Equipment called a “seismograph” is used to record and measure seismic vibrations that occur during earthquakes. The data produced by seismographs helps scientists understand earthquake characteristics, such as magnitude, depth, and hypocenter location.
Seismic Modeling: Scientists use computers and mathematical models to predict the movement of seismic waves through the Earth’s crust. This helps in understanding how these waves propagate and interact with various rock layers.
Earthquake Source Study: Seismologists identify the causes of earthquakes, such as the movement of tectonic plates or volcanic activity. They also study the characteristics of earthquakes, such as fault patterns or deformation of the earth’s crust.
Behavior of Rock Materials: Seismology also involves the study of the physical and mechanical properties of the rocks that form the earth’s crust. This helps in understanding how rocks behave when subjected to stress and pressure.
Early Warning Systems: Seismologists contribute to the development of early warning systems for earthquakes. By detecting the initial vibrations from an earthquake, this system can provide warnings to the public before an earthquake reaches the affected area.
Earthquake Impact Studies: Seismologists also study the social, economic, and environmental impacts of earthquakes. This involves analyzing damage to structures, infrastructure and ways to reduce the risk of future impacts.
Volcanic Activity Monitoring: Seismologists are also involved in monitoring volcanic activity, as volcanic eruptions are often associated with earthquakes.
All research and analysis in the field of seismology aims to understand earthquake phenomena in more depth, help reduce the risk of their impact, and provide valuable information for the protection and safety of society.
Earthquake Impact:
Earthquakes can have devastating impacts on the environment and humans. Vibrations from earthquakes can damage buildings, infrastructure and cause landslides. Large earthquakes can also cause tsunamis if they occur under the sea or near the coast. Apart from that, earthquakes can also trigger the release of natural gas or magma from volcanoes.
Earthquake Risk Reduction
To reduce the risk impact of an earthquake, many actions can be taken. Buildings and infrastructure must be designed with good earthquake resistance. Public education about correct actions during an earthquake is also important, such as taking shelter in a safe place and avoiding tall buildings and heavy objects during an earthquake.
Research and Monitoring
Scientists and researchers continually monitor seismic activity to understand more about the behavior of earthquakes. Early warning systems were also developed to notify the public before a major earthquake occurs, giving time to take safety measures.
Those are some basic concepts about earthquakes. We hope this explanation is useful for you in understanding this complex phenomenon. If you have any further questions, don’t hesitate to ask!
Causes of Earthquakes
Earthquakes are caused by the movement or sudden release of energy in the earth’s crust. There are several main causes of earthquakes, the most common of which are:
Tectonic Plate Shift: This phenomenon is the main cause of earthquakes. The Earth’s crust is made up of several tectonic plates that move slowly over time. When these plates interact with each other, there can be overlap, lateral drift, or even one plate diving beneath another plate in a process called subduction. During this process, energy builds up due to friction between the plates. When the accumulated energy exceeds the resistance limit of the rock, a sudden release occurs which creates an earthquake.
Volcanic Activity: Volcanic activity can also cause earthquakes. When magma moves through volcanic channels, it can damage the surrounding rock. The pressure and movement of this magma can create vibrations called volcanic earthquakes. Additionally, when a volcano erupts, the release of pressure can cause powerful volcanic earthquakes.
Fault: A fault is a crack in the earth’s crust where two blocks of rock move relative to each other. When pressure due to plate movement or other geological activity causes these cracks to move suddenly, energy is released in the form of an earthquake.
Mud Earthquakes (Induced Seismicity): Human activities, such as drilling for oil and gas, filling and unloading water reservoirs, or dumping liquid waste into the ground, can change the pressure in the earth’s crust and cause earthquakes. This phenomenon is known as “mudquake” or “induced seismicity”.
Marine Tectonic Earthquakes (Tsunami Seismicity): The release of energy under the sea, especially under oceanic plates, can create earthquakes that trigger large vertical movements on the seafloor. This can cause a tsunami, a large wave in the sea that can travel quickly and reach the coast with great destruction.
All of the above causes result in the release of energy in the form of seismic waves that propagate through the earth’s crust and cause vibrations on the surface. In many cases, earthquakes are the result of a complex interaction of several of the above factors.
Earthquake & Tsunami
Earthquakes and tsunamis are closely related because many tsunamis are triggered by earthquakes. This connection relates to the way earthquakes can affect the water in the ocean or sea, which in turn can create tsunami waves. The following is a further explanation of the relationship between earthquakes and tsunamis:
Subduction Earthquakes: Many tsunamis result from earthquakes that occur under the sea at subduction zones. Subduction zones occur when one tectonic plate sinks beneath another plate. When these plates are shifted or squeezed, a huge release of energy occurs. This can trigger large vertical movements of the sea floor, disturbing the water above and creating tsunami waves.
Plate Shifting Under the Sea: Earthquakes that occur on the seafloor and involve shifting plates can also cause tsunamis. Sudden movements of the earth’s crust under the sea can displace large amounts of water, creating tsunami waves that travel towards the coast.
Volcanic Earthquakes: Volcanic activity involving eruptions or movement of magma can cause earthquakes. These earthquakes can also affect water near the coast and trigger tsunami waves, especially if volcanic eruptions occur under the sea.
Earthquakes in Seamounts: Some earthquakes occur in seamounts, where geological processes create pressure and sudden movements that can trigger tsunami waves.
In all the cases above, the primary mechanism is a sudden shift that creates a major change in the water in the sea or ocean. Tsunami waves can travel far out to sea in the form of long, low waves, but as they approach the coast, these waves close together and can rise dramatically, creating large waves and danger to coastal areas.
It is important to remember that not all earthquakes will trigger a tsunami, but large earthquakes under the sea or near the coast have great potential to do so. Therefore, it is important for authorities in areas at risk of earthquakes and tsunamis to have effective early warning systems and evacuation plans to protect the population from these dangers.
How to Save Yourself When an Earthquake Strikes
Properly saving yourself when you feel an earthquake is very important to minimize the risk of injury or harm. Here are steps you can take to improve your safety during an earthquake:
Stay Calm. Try to maintain your calm so you can think clearly and take appropriate action. Avoid panicking and running carelessly. Rushing and careless steps can increase the risk of injury.
Look for shelter. If indoors or in a building, protect yourself by taking cover under a sturdy table or chair. Avoid windows, glass, walls that might collapse, and heavy objects that could fall. If you are outside, look for an open area, away from buildings, power poles, large trees, and structures that might fall. If you are near tall buildings or large construction, stay away from them. Tall buildings are vulnerable to damage during earthquakes.
If you are in a coastal area and feel a strong earthquake, immediately move to higher ground, because an earthquake under the sea can trigger a tsunami.
Avoid being near windows, glass and mirrors during an earthquake. This prevents the danger of glass shards that could be thrown during an earthquake.
Do not use elevators during an earthquake. Elevators can become stuck or damaged and increase the risk of getting trapped.
Avoid being near damaged buildings or structures that collapsed during the earthquake. This includes pedestrian paths under bridges.
After the main earthquake, there may be aftershocks or aftershocks. Stay alert and continue to follow safety measures.
Listen to Official Information: If possible, listen to local authorities or authorities. They can provide important guidance and instructions regarding safety measures.
Remember that every earthquake situation is different, so there are always unique factors to consider. Knowing safety measures and practicing them regularly can help you feel better prepared for an earthquake.
