Earthquakes

Written by: Caroline Kim

February 25, 2023

In light of recent events, it’s clear that earthquakes can leave severe damage to humans, wildlife, and the environment. Today, we’ll look into the initial and lasting damages of an earthquake on the ecosystems and global health.

Fundamentally, earthquakes are characterized by a slipping of two transform boundaries; this slipped area is known as the “fault plane” and the point in which the earthquake starts is known as the epicenter (Wald). A series of earthquakes may consist of foreshocks, mainshock, and aftershocks which can continue on for as long as years (Wald). Fundamentally, these slipping plates and the friction are what cause the earth to shake and cause the damage that it does. There are certain factors that influence the impact and lasting effects of an earthquake, including magnitude, duration, geography, time, and intensity (Russell).

Some environmental and geographical impacts include ground shaking, surface faulting, liquefaction, and tsunamis (earthquake hazards). Ground shaking is probably the most obvious, being the ground vibration from the seismic waves initiated by magnitudes of fault ruptures(earthquake hazards). Surface faulting refers to the “... differential movements caused by deep-seated forces in the Earth” (earthquake hazards). According to the U.S. Geological Survey, ”Liquefaction… is a physical process that takes place during some earthquakes that may lead to ground failure” and can result in clay free soil deposit (sand/silt) may behave as a thick liquid rather than solid (earthquake hazards). Some ground failures that may result include lateral spreads (movement of large soil chunks), flow failures , and loss of bearing strength (earthquake hazards).

The question is, how do these ramifications of earthquakes tie into the environment? In terms of weather, “... the only correlation that’s been noted between earthquakes and weather is that large changes in atmospheric pressure caused by major storms… shown to occasionally trigger… “slow earthquakes,” which release energy over comparatively long periods of time and don’t result in ground shaking like traditional earthquakes do” (Buis). But a more inquiring connection to earthquakes is climate. A study by Lundgren mentions… “The largest climate variable that could change fault stress loads is surface water in the form of rain and snow” but that is only seen in microseismicity (tiny/unnoticeable earthquakes) (Buis). One thing that seems to impact earthquakes are alternating periods of drought and heavy precipitation as well as aquifers, which alter stress on earth’s crust (Buis). Other influences to tectonic activity include glaciation, which can impact “subsurface magma” (Buis). Even while further studies are necessary, many of these proposals and observations offer insight into our earth’s system.

As we’ve seen, earthquakes have an enormous impact on global health beyond the environment. Structures, humans, and natures alike are all at risk. Potential infectious diseases from earthquakes include but are not limited to respiratory, water-borne, ski, and vector-borne illnesses (Mavroulis). According to a study, risk factors include damaged infrastructure that is left damaged for extended periods, prolonged exposure to contamination, poor education of disease prevention (Mavroulis). It’s clear that while prevention is challenging when it comes to earthquakes, efficient preparation and action can help improve safety for humans in the case of such a disaster.

Sources:

Wald, Lisa, and Earthquake Hazards. “The Science of Earthquakes | U.S. Geological Survey.” U.S. Geological Survey, https://www.usgs.gov/programs/earthquake-hazards/science-earthquakes.

Russell, Jeffrey. “Earthquakes.” World Health Organization, World Health Organization, https://www.who.int/health-topics/earthquakes#tab=tab_1.

Earthquake Hazards. “What Are the Effects of Earthquakes?” What Are the Effects of Earthquakes? | U.S. Geological Survey, https://www.usgs.gov/programs/earthquake-hazards/what-are-effects-earthquakes.

Mavroulis, Spyridon, et al. “Impact of Earthquakes and Their Secondary Environmental Effects on Public Health.” NASA/ADS, Apr. 2017, https://ui.adsabs.harvard.edu/abs/2017EGUGA..19.3884M/abstract.

Buis, Alan. “Can Climate Affect Earthquakes, or Are the Connections Shaky? – Climate Change: Vital Signs of the Planet.” NASA, NASA, 29 Oct. 2019, https://climate.nasa.gov/news/2926/can-climate-affect-earthquakes-or-are-the-connections-shaky/.