What You Need to Know About the 4.2 Magnitude Earthquake in Southern California
FOKUS NEWS - On January 5, 2024, a 4.2 magnitude earthquake shook Southern California, causing no significant damage or injuries. The quake was felt across Los Angeles and Orange counties, as well as parts of San Bernardino and Riverside counties. The epicenter was located near Lytle Creek, in the San Gabriel Mountains, about 45 miles east of downtown Los Angeles. The quake was followed by several aftershocks, the largest of which was a 3.5 magnitude tremor.
1. How Common Are Earthquakes in Southern California?
Southern California is one of the most seismically active regions in the world, due to its location along the boundary of the Pacific and North American tectonic plates. These plates are constantly moving and sliding past each other, creating stress and friction that build up along faults. When the stress exceeds the strength of the rocks, the faults rupture and release energy in the form of seismic waves, which cause the ground to shake.
According to the U.S. Geological Survey (USGS), Southern California experiences about 10,000 earthquakes each year, most of which are too small to be felt. However, some of these quakes can be large and destructive, such as the 1994 Northridge earthquake (magnitude 6.7), the 1971 San Fernando earthquake (magnitude 6.6), and the 1933 Long Beach earthquake (magnitude 6.4). These quakes caused billions of dollars in damage and hundreds of fatalities.
2. How Are Earthquakes Measured and Reported?
Earthquakes are measured and reported using two main parameters: magnitude and intensity. Magnitude is a measure of the amount of energy released by an earthquake, based on the amplitude of the seismic waves recorded by seismometers. Magnitude is usually expressed using the Richter scale, which assigns a numerical value from 0 to 10, with each unit representing a tenfold increase in energy. For example, a magnitude 5 earthquake releases 10 times more energy than a magnitude 4 earthquake, and 100 times more energy than a magnitude 3 earthquake.
Intensity is a measure of the effects of an earthquake on people, buildings, and the environment, based on the observations and reports of eyewitnesses. Intensity is usually expressed using the Modified Mercalli scale, which assigns a Roman numeral from I to XII, with higher numbers indicating more severe shaking and damage. For example, an intensity I earthquake is barely felt by anyone, while an intensity XII earthquake causes total destruction and may be accompanied by landslides, liquefaction, and tsunamis.
The USGS publishes the magnitude and intensity of earthquakes on its website, as well as maps, graphs, and other information. The USGS also issues alerts and notifications to the public and emergency responders, using the ShakeAlert system, which provides early warnings of potentially damaging earthquakes.
3. What Are the Impacts and Risks of Earthquakes in Southern California?
Earthquakes can have various impacts and risks, depending on their magnitude, intensity, location, depth, and duration. Some of the possible impacts and risks are:
- Ground shaking, which can cause buildings, bridges, roads, pipelines, and other structures to collapse, crack, or shift. Ground shaking can also trigger landslides, rockfalls, and avalanches, which can bury or damage structures and people.
- Ground displacement, which can cause permanent changes in the elevation, position, or shape of the land. Ground displacement can also create surface ruptures, which are visible breaks or offsets along faults. Surface ruptures can damage structures and infrastructure that cross them, such as roads, railways, and pipelines.
- Liquefaction, which is a phenomenon where loose, saturated soil loses its strength and behaves like a liquid when shaken by an earthquake. Liquefaction can cause buildings and other structures to sink, tilt, or collapse, as well as create sand boils, which are fountains of water and sand that erupt from the ground.
- Tsunamis, which are large waves generated by underwater earthquakes, landslides, or volcanic eruptions. Tsunamis can travel across oceans and cause flooding, erosion, and damage along the coastlines. Tsunamis can also affect harbors, ports, and marinas, where they can damage or sink boats and ships, and create strong currents and whirlpools.
- Fires, which can be ignited by broken gas lines, electrical wires, or other sources of heat or sparks. Fires can spread rapidly and consume buildings, vegetation, and other combustible materials. Fires can also create smoke and ash, which can reduce visibility and affect air quality and health.
- Human casualties, injuries, and fatalities, which can result from the direct or indirect effects of earthquakes, such as falling debris, flying glass, collapsing structures, landslides, liquefaction, tsunamis, fires, or panic. Human casualties can also be caused by the lack of access to medical care, water, food, shelter, or communication, due to the disruption of infrastructure and services.
- Economic losses, which can result from the damage or destruction of buildings, infrastructure, and other assets, as well as the loss of productivity, income, and revenue, due to the interruption of business and economic activities. Economic losses can also be caused by the cost of recovery, reconstruction, and mitigation, as well as the loss of tourism, trade, and investment, due to the deterioration of the image and reputation of the affected area.
4. What Can You Do to Prepare for and Protect Yourself from Earthquakes in Southern California?
There are several steps you can take to prepare for and protect yourself from earthquakes in Southern California, such as:
- Before an earthquake, you should:
- Learn about the earthquake hazards and risks in your area, and how to receive and respond to earthquake alerts and warnings.
- Make an emergency plan and kit, and practice how to use them. Your plan should include how to communicate and reunite with your family and friends, and where to go and what to do in case of an earthquake. Your kit should include water, food, first aid supplies, flashlight, radio, batteries, cash, and other essential items.
- Secure your home and workplace, and make them more earthquake-resistant. You should anchor heavy furniture and appliances to the walls or floor, and secure hanging or loose objects, such as pictures, mirrors, shelves, or lamps. You should also identify safe and dangerous places, such as under sturdy tables or desks, or near windows or fireplaces.
- Review your insurance policies, and make sure they cover earthquake damage and losses. You should also keep copies of your important documents, such as identification, bank accounts, and property deeds, in a safe and accessible place.
- During an earthquake, you should:
- Drop, cover, and hold on. You should drop to the ground, cover your head and neck with your arms, and hold on to something sturdy, such as a table or desk, until the shaking stops. You should avoid running outside or standing in doorways, as they may not be safe or stable.
- If you are indoors, stay inside until the shaking stops and it is safe to exit. You should use the stairs, not the elevator, and be aware of falling debris, broken glass, or damaged utilities. You should also check yourself and others for injuries, and provide first aid if needed.
- If you are outdoors, move away from buildings, trees, power lines, or other potential hazards. You should find an open and clear area, and drop to the ground, covering your head and neck with your arms. You should also stay alert for aftershocks, which can be smaller or larger than the main quake.
- If you are in a vehicle, pull over to the side of the road, and stop in a safe and clear place. You should avoid bridges, overpasses, tunnels, or underpasses, as they may collapse or be damaged. You should also stay inside your vehicle, with your seat belt fastened, and turn off the engine. You should listen to the radio for updates and instructions, and do not resume driving until the shaking stops and it is safe to do so.
- After an earthquake, you should:
- Be prepared for aftershocks, which can occur minutes, hours, days, or weeks after the main quake. You should follow the same procedures as during the earthquake, and stay alert for any signs of danger or damage.
- Check your home and workplace for any structural damage, gas leaks, water leaks, or electrical problems. You should also turn off the main valves or switches, if you suspect any damage or smell any gas. You should not use open flames, matches, or lighters, as they may ignite gas or cause explosions.
- Contact your family and friends, and let them know you are safe and where you are. You should also follow the instructions and advice of the authorities, and do not enter or cross any restricted or hazardous areas. You should also avoid spreading or believing any rumors or false information, and rely on official sources for updates and guidance.
- Help others who may need assistance, such as the elderly, children, people with disabilities, or people who are injured or trapped. You should also cooperate with the emergency responders, and volunteer or donate if you can. You should also seek emotional support or counseling, if you feel stressed, anxious, or traumatized by the earthquake.
I hope you find this article helpful and informative. Thank you for your interest in earthquakes and how to prepare for them. If you have any questions or feedback, please feel free to contact me.