Showing posts from November, 2021

Earthquake Hazards: Release of Hazardous Materials

 Just as an earthquake can damage or destroy buildings, cause liquefaction , landslides , seiches , fires , flooding , dam failures , and tsunami, the shaking can cause the release of hazardous materials. This release can happen as hazardous material storage tanks or containers are damaged. And don't be complacent and think only facilities that manufacture hazardous materials are at risk.   Many manufacturing and other facilities use various hazardous materials throughout their processes, and a tremor could cause the release of these materials through damaged or destroyed distribution or storage systems.  One consideration, which you have no real control over, is the transportation of hazardous materials. While uncommon, accidents involving vehicles with hazardous materials--which include trucks and railcars--do happen. In these accidents, depending on the hazardous material(s), whole blocks, neighborhoods, or even sections of a city may be put on lockdown or evacuated. The potenti

Earthquake Hazards: Landslides and rockfalls

The obvious hazard of an earthquake is the shaking of the ground. I'm not aware of anyone being killed directly by the ground shaking. The exception might be when the ground opens up. There have probably been some indirect deaths of the earth shaking if someone died from a heart attack. Most of the injuries and deaths are the result how the ground shaking affects other things. These are the earthquake-related hazards. Shaking of the earth shakes buildings. This is the obvious earthquake hazard. Related to the collapse of man-made structures is the threat of the destabilization of the ground. One of these hazards is liquefaction . Other earthquake-related hazard caused by ground destabilization, which many people don't consider but which becomes obvious when mentioned, are landslides and rockfalls. While landslides and rockfalls are similar, rockfalls are primarily when only rocks (which can small or large) are what come down. Landslides are the downward sliding of a mass of ear

A super-eruption may not give warning

 A large natural lake, called Lake Toba, in North Sumatra, Indonesia peacefully fills what is actually an ancient caldera of a supervolcano. Volcanic eruptions can affect a wide swath of the world, depending on the size of the eruption. Ash launched high into the atmosphere affects air travel with aircraft avoiding the ash clouds, or areas where ash could potentially be present. The ash particulates can not only affect visibility, they can also cause a lot of damage to an aircraft engine.  I was living in Federal Way, Washington in 1980 when Mt. Saint Helens erupted. We were too far away to see it. I remember about a week later there was a grayish dust over some of the things in our backyard. Turns out it was ash dust that had travelled around the world before it settled down. Supervolcanoes are one of the disasters that would seriously affect much of the world. Thankfully scientists estimate there are only 5-10 volcanoes in the world that are capable of super eruptions. The bad news i

Earthquake Hazards: Liquefaction

With the focus on earthquakes so often on the shaking and potential infrastructure and building damage, there are other hazards the shaking causes that are sometimes overlooked or minimized. One of those hazards is liquefaction. Liquefaction is one of the earthquake hazards I'm more concerned about where I live because according to the liquefaction-potential maps, my home is in an area with high liquefaction probability.  So, what is liquefaction?   When soil is saturated, or partially saturated, it can act like a liquid when it is sufficiently agitated or shaken (like, by an earthquake). Loose sand and silt-based soils are most susceptible. As the earth shakes, the soil loses its strength and stiffness and begins to behave more like a liquid, where anything on the surface could sink or move. Even the liquefaction of buried layers of soil can cause these problems. As a side note, one of the parables taught by Jesus in the New Testament (Matthew 7:24-27) was about a wise man buildin