| Disaster Rally

Effects of Acid Rain on the Environment and Human Health

From the dawn of humanity, people hoped for, prayed for and celebrated the coming of rain. Most of the time. Aside from the damage of torrential rains and floods, precipitation brings life to crops and livestock. Humans, too, require water to survive. Modernity, however, found a way to make rain an unwelcome thing. The sulfur and nitrogen pumped into the atmosphere by power plants, factories, vehicles and industrial machinery acidify falling moisture. Pure water turns toxic and corrosive.

Effects of Acid Rain on the Soil

Acid rain is composed of either sulfuric acid or nitric acid. In fact, both may be present. At any rate, it can do harm as soon as it hits the ground. On one hand, soil has a built-in defense known as “buffering capacity” that keeps its alkalinity stable. Still, the combination of naturally present acids with acid rain can overwhelm this mechanism.

High-alkaline precipitation can stunt the nutritional production of organic matter and, worse, cause nutrients to be leached from the soil. Furthermore, poisonous elements like aluminum more easily run off when the pH balance is low. All in all, soil is less fertile, more prone to erosion and sometimes toxic. Sadly, the damage does not stop there.

Effects of Acid Rain on Plants

effects of acid rain on soil and vegetation — Image Source: World Atlas

If soil suffers from the adverse effects of acidic precipitation, it stands to reason that plant life is likewise infected. The science confirms it. Acid rain not only robs the ground of nutrients. It diminishes the ability of root structures to take up what sources of nourishment might be left. Of course, some plants are better able to adapt than others. Trees, crops, flowers and herbs all have different needs and abilities.

Nevertheless, this phenomenon not only harms plants from the ground up. Acid rain falls directly on leaves and branches, destroying the coatings that protect them from the elements. In addition, the rain ravages the chloroplasts essential for photosynthesis. Without a sufficient number, plants will die. Simply stated, acid rain menaces vegetation from above and below.

Effects of Acid Rain on Wildlife

Some species of fauna are better-suited to tolerate acid rain than others. Certain insects, for example, show little disturbance from it while others die off. Fish, by contrast, decline in vigor, fertility and overall numbers because of acid rain. Harmful metals like mercury and aluminum increase in lakes, rivers and streams. In the case of aluminum, the element can attach to fish gills and cause respiratory difficulties.

Aquatic reptiles and amphibians lay eggs but their embryos can not endure where pH levels decline below 4.5 (seven signifying neutrality). Moreover, mammals suffer from acid rain when they lose vegetative cover against predators and storms. They also lose habitat in which to nest and breed. Food sources shrink, as well. Animal populations can not long thrive without these necessities of life.

Effects of Acid Rain on Humans

Some believe that because humans can swim in an acidic lake without incident that acid rain is not a threat. This, however, is only a half-truth. The noxious raw materials of acid rain – sulfur dioxide and nitrogen oxides – are as pernicious to people as the low-pH rain is to fish. When borne by the air these compounds induce respiratory disorders like bronchitis and asthma.

Also, nitrogen oxides can yield ground-level ozone, a primary cause of pneumonia and other pulmonary problems such as COPD. Where acid rain is falling, these unhealthy, hardly noticeable gases are permeating the air we breathe. While the precipitation itself is less detrimental, its causes are much more so, if not lethal.

Effects of Acid Rain on Buildings

A building effected by acid rain in Copola, Mexico. (Image Source: Emaze)

Acid rain demonstrably corrodes buildings made from marble, sandstone and limestone. Public statues likewise degrade because of the impact of acidic precipitation. Nitric, sulfuric and sulfurous acid react with the materials in these edifices, causing engraving to fade. These reactions also cause blackening, peeling and crumbling. In many buildings, sharp edges eventually round off and gypsum is formed, badly discoloring the structures.

Several heritage sites around the world are imperiled by acid rain. These include the Taj Mahal in India, Hadrian’s Arch in Greece and the Leshan Buddha in China. Most of these structures were built before anyone could have imagined acidic rainfall. Multiple efforts are underway to save these edifices.

Effects of Acid Rain on Infrastructure

Not only buildings and statues receive the punishing impact of acid rain. Steel bridges, waterway locks and railroads similarly corrode from steady exposure. In addition to steel, bronze, copper, nickel and zinc are susceptible to damage from rains with a pH as high as 3.5. Mild, galvanized and stainless steel suffer from oxidation-reduction reaction when hit with acid rain. Aside from the transfer of electrons, this means the material deteriorates.

Relative to transportation and public utilities, such corrosion has enormous economic and public safety implications. While buildings and infrastructure are not part of the natural world, they do compose human habitat and immediate environment. Their sustainability, accordingly, is an environmental concern.

Effects of Acid Rain on Visibility

The sulfur and nitrogen emissions that cause acid rain also bear negatively on visibility. In fact, their particles impair perceptibility and clarity by as much as 70 percent in the eastern United States. In the west, sulfates have contributed to visibility decline in national parks like the Colorado River Plateau and the Grand Canyon. With reductions of visual discernment in these locations, the problem can not be blamed simply on urban smog. Particulates from sulfur dioxide and nitrogen oxides travel far and wide to wreak environmental havoc.

Summing Up

Whether degrading nature or the bastions of civilization, acid rain is a serious issue requiring sober action. Burning fuels cleaner, employing alternative energy sources and simply conserving resources altogether are achievable first steps. Using electric cars and public transportation reduce the need for fossil fuels. Finding new ways to protect structures, preserve soil and treat rainwater are also necessary, but need research and development. The only option that is unacceptable is to do nothing.

Fukushima Daiichi Nuclear Disaster Facts You Should Know

The harnessing of nuclear power is a fitting tribute to the impressive ingenuity of the human race. Abundant electricity the world over—otherwise generated by fossil fuels—is a product of nuclear power. While devastating accidents show up in the history of nuclear energy, each has nevertheless inspired new safeguards and preventions. Nature, however, can override our resourcefulness. It can also remind us of our limits. The disaster at Fukushima Daiichi reminds us in seven ways.

1. Meltdown of Three Reactors

On March 11, 2011, an earthquake registering at 9.0 on the Richter scale caused severe seismic disruption in east Japan. Centered 130 km to the east of Honshu Island, the quake endured for three minutes. It also triggered horizontal movement of the tectonic plates beneath the sea. This unsettling gave birth to a tsunami that ultimately flooded 560 square miles. While taking 19,000 lives, it ruined over a million structures. Destruction remains even now.

Significantly, this region is home to four nuclear power plants, operating eleven reactors among them. When the earthquake began, all of them shut down as programmed in the event of an emergency. Within a few days, eight of the eleven reactors achieved “cold shutdown.” This means the coolant system dropped below 200˚F and reached atmospheric pressure. At Fukushima Daiichi, however, three reactors—and their cooling systems—lost power as the tsunami flooded that facility. The back-up generators also ceased functioning. Thus the mechanisms for dumping waste heat and decay heat did not kick in, leaving the reactor cores vulnerable to meltdown.

2. Rated a “Major Accident”by IAEA

The danger and consequences related to the Fukushima Daiichi nuclear disaster facts are underscored by the International Atomic Energy Agency (IAEA). Using a ranking known as the International Nuclear Event Scale (INES), the IAEA had a range of designations from which to choose. INES labels the least consequential events of no significance, or simply anomalies. At the far end of the scale are “serious accident” and, worst of all, “major accident.” The episode at Fukushima Daiichi received the latter.

In determining an INES rating, the IAEA uses three factors: 1) how the event affects people and the environment; 2) the status of radiological controls and protection; and 3) defense in depth, or the operation of redundant layers of safeguards. Fukushima Daiichi ranked the most dangerous because of the high level of radioactive emissions. Four to six days after the earthquake, instruments detected 940 peta–becquerels (standard measuring unit for radioactive releases).

3. Four Reactors Out of Commission

Among the lesser known Fukushima Daiichi nuclear disaster facts is that a fourth reactor—shut down the previous autumn for repairs—suffered an explosion four days later. The cause of this accident was the rising hydrogen in unit 3, with which unit 4 shared ducts. Unit 4 therefore received the backflow from an overheating core. This blast destroyed the top of the facility and further impaired unit 3. According to the INES scale, the explosion at unit 4 earned a 3 rating—a “serious incident.” Units one through three did not enter cold shutdown status until nine months later.

4. Three Energy Executives Charged

Earthquakes and tsunamis are phenomena beyond human control. Thus it is easy to assume that the company operating the nuclear facility would face no liability. Not quite. An examination of the Fukushima Daiichi nuclear disaster facts led Japanese authorities in 2017 to indict three leaders of the Tokyo Electric Power company (Tepco) on the grounds of professional negligence. Evidence indicates that the executives had access to prophetic information. Simulated studies accounted for a similar-size tsunami based on the same earthquake magnitude as that of March, 2011. Worse, this research also predicted a power outage and resulting meltdowns. The Japanese government contends that the three men apathetically discarded the study in spite of its dire warnings.

5. Tracking Radioactive Leaks

The primary concern among the Fukushima Daiichi nuclear disaster facts under review was the dispersal of volatile iodine-131 and caesium-137 into the air and water. These fission products are known to affect long-term contamination in the soil and in lakes, rivers and streams. Yet managers were faced with a major challenge: the same tsunami that knocked out the cooling systems also rendered the emission monitoring systems inoperative. Neither the government nor Tepco could establish certainty as to the concentration of emissions or hazardous content of leaks. Nevertheless, educated guessing determined that runoff from the site into the ocean exceeded safe levels of radionuclides, i.e. atoms with unstable nuclei.

6. No Deaths from Radiation Sickness

It was one of the worst atomic accidents ever. Yet surprising Fukushima Daiichi nuclear disaster facts reveal that no deaths or illnesses due to radiation were reported. The swift evacuation of 150,000 residents within a 20 km radius of the power plant likely gets credit for this happy outcome. There is a fine line, however, between quick thinking and haste. Evacuation stress may very well be complicit in at least a thousand deaths—mostly elderly persons— during the exodus.

7. Return and Reconstruction

Less surprising is the slow pace of recovery in the ensuing years. The first wave of repopulation began three years after the accident. Each subsequent year, other towns and sections were re-opened for habitation. Many people chose not to return. During the years immediately following the disaster, the government subsidized evacuees to the tune of 7.54 trillion yen to date. Those subsidies will soon phase out so some may have no chance but to go back to their homes near the plant. This bleak prospect is one of the Fukushima Daiichi nuclear disaster facts that the world may not know about.

Summing Up

In an age where the policy makers of the world seek to employ cleaner energy sources, nuclear power is a logical alternative…until accidents occur. Whether by natural forces, human error or technological glitch, malfunctions at nuclear plants yield serious repercussions and long-term ecological damage. Fukushima Daiichi is proof positive.

Image from depositphotos.com.

10 Catastrophic Man-Made Environmental Disasters

Human activity is responsible for some devastating attacks on the natural world. Many of these man made environmental disasters could have been avoided if not for human greed, negligence, and carelessness. Here are ten of the world’s worst man made environmental disasters, listed chronologically.

1. Nuclear Testing at Bikini Atoll

Operation Crossroads Baker — Image Source: Wikipedia

Bikini, or Pikinni, Atoll is an island group in the Marshall Islands chain. The man made environmental disasters on the ring of islands began in 1946 when the U.S. began testing nuclear weapons there. Twenty-three devices were exploded between 1946 and 1958 on and around the islands. As a result, 167 Marshallese residents of the islands were forced to relocate. Bikini Atoll is no longer suitable for human habitation as a result.

Residents of nearby Utrik Atoll suffered acute radiation sickness. So did the 23 fishermen and crew members aboard the Japanese vessel the Daigo Fukuryū Maru. The ship’s radio operator, Aikichi Kuboyama, died as a result. Wildlife including the atoll’s coral reef were severely affected, with the effects still being present as recently as 2017. Nurse sharks are still being born with mutations caused by exposure to radiation.

2. Minamata Disease

Old picture of Chisso Corporation, Japan, responsible for one of the greatest man made environmental disasters — Chisso Corporation (Image Source: CARI Infonet)

In 1956, residents of the town of Minamata in Japan began experiencing neurological symptoms of mercury poisoning. They were exposed to toxic levels of mercury from eating the fish out of Minamata Bay, which was contaminated by industrial pollution by the Chisso Corporation. To this day, Chisso Corporation makes compensation payments to the victims. More than 2,200 people died as a result of methylmercury contamination.

3. Love Canal

Love Canal, Niagara Falls, New York — Image Source: Pinterest

Love Canal was a planned community in Niagara Falls, New York. William T. Love, the town’s eponymous planner, fell into financial difficulties, and the canal was used as a landfill and for dumping industrial waste. In the early 1950s, the dump was closed. Around the same time, the town experienced an economic and population boom. Families moved in and began having children.

Residents had long complained about unusual smells, substances, and an oily black runoff present in their yards and fields around the town, especially around the canal. Unknowingly, residents were being exposed to toxic industrial runoff, including benzene, dioxin, PCBS, toluene, and chloroform. They suffered a greater than average number of miscarriages, birth defects, neurological conditions, and abnormal white blood cell counts that can be a precursor to leukemia.

On August 7, 1978, then-president Jimmy Carter declared the site a federal health emergency. A 1979 study showed the 33 percent of Love Canal residents suffered chromosomal damage, compared to about one percent of the U.S. population as a whole.

4. The Amoco Cadiz Oil Spill

On March 16, 1978, the oil tanker Amoco Cadiz hit a rock off the coast of Brittany, France. This caused the control room to flood and led to the sinking of the ship. The shipwreck resulted in the spilling of 1.6 million barrels of light crude oil and 4,000 tons of fuel oil spilling into the Atlantic Ocean. Although the Deepwater Horizon disaster released more oil, the Cadiz disaster resulted in the greatest loss of aquatic wildlife as a result of an oil spill in human history.

5. Bhopal Disaster

Bhopal Disaster, India — Image Source: theCHIVE

On December 2, 1984, an industrial accident at the Union Carbide India Limited pesticide plant released methyl isocyanate into the air. It caused the worst industrial disaster in the world’s history. Between 2,200 and 3,700 were killed by the gas release, an additional 558,000 were injured, and 3,900 were permanently disabled. An estimated 8,000 people died within two weeks of the release of the gas, mostly from respiratory failure. Inadequate safety equipment contributed to the disaster.

Drinking water is contaminated since pesticides from the now-abandoned plant have seeped into it. It was estimated in 2014 that 120,000 people still live with health effects of the disaster.

6. The Great Pacific Garbage Patch

This floating example of man made environmental disasters was discovered some time between 1985 and 1989. The currents of the North Pacific Gyre (a marine ecosystem) trap particles of marine debris that includes chemical sludge and pelagic plastics. These particles are so small they can be hard to detect with the naked eye and can’t be seen using satellite photography. Although this makes it difficult to estimate the size of the debris field, some researchers believe it may be as large as eight percent of the total area of the Pacific Ocean.

Scientists believe the origin of these plastics is littering and improper industrial waste disposal. This includes the disposal of nets and other gear used by the fishing industry. The effects of the Great Pacific Garbage Patch aren’t fully known. However, the particles that compose it are small enough to be ingested by marine wildlife which then enter the food chain. Byproducts of the breakdown of plastics include toxic molecules such as bisphenol A (BPA) and polystyrene derivatives.

7. Chernobyl Disaster

Danger sign at the Chernobyl nuclear power plant — Image Source: Pinterest

On April 26, 1986, the Chernobyl nuclear power plant in Pripyat, Ukraine (then part of the USSR) experienced an uncontrolled reaction incident, resulting in a steam explosion followed by a fire. Updrafts resulting from the fire released nuclear fission materials into the atmosphere. It contaminated the environment of the western USSR and parts of Europe.

The investigation revealed this man made environmental disaster was caused by design flaws at the plant and operator errors made during a shut-down safety test. Further errors were made in trying to contain the accident. Firefighters who arrived on scene weren’t told that they were entering the scene of a nuclear accident; they thought they were responding to an electrical fire. Nor was Pripyat evacuated immediately.

Two employees of the plant died immediately at the scene, 28 more of acute radiation sickness, and 14 more died of exposure to the radiation over the next decade. Four kilometers of forest died and the water system became contaminated. Furthermore, fish in the rivers were inedible for years afterward due to radioactive contamination. It is difficult to estimate how many people died as a result of the accident since there was a systematic cover-up by the Soviet Union. However, as many as 9,000 may have died from acute radiation sickness and long-term exposure to radioactivity. This makes the Chernobyl incident among the deadliest of man made environmental disasters.

8. The Exxon Valdez Oil Spill

Exxon Valdez Oil Spill, Bligh Reef in Prince William Sound off the coast of Alaska — Image Source: Imgur

On March 24, 1989, an oil tanker ship named the Exxon Valdez struck the Bligh Reef in Prince William Sound off the coast of Alaska. The shipwreck caused more than 10.8 million gallons of crude oil to spill into the sound.

As many as 250,000 seabirds died as a result. Sea otters, river otters, bald eagles, salmon, herring, and orcas were some of the other species whose long-term health and survival rates were affected. Additionally, the 2-butoxyethanol used in the clean-up caused health problems for the clean-up crew.

An investigation determined the cause of the shipwreck to be an insufficient number of crew members, an overworked crew, and a steering error by the third mate. At that time, Exxon Shipping Company regularly overworked and undermanned its oil tankers, a recipe for man made environmental disasters.

9. Kuwaiti Oil Fires

Kuwaiti Oil Fires, a result of the first Persian Gulf War in 1991 — Image Source: Wikipedia

This man made environmental disaster was a result of the first Persian Gulf War in 1991. Iraqi military forces retreating from Kuwait, the country Iraq had unlawfully invaded, set fire to between 600 and 732 Kuwaiti oil wells, oil lakes, and trenches. This act of sabotage resulted in severely reduced air quality for the people and wildlife of Kuwait and the surrounding countries. More than 40 million tons of earth and sand were contaminated with oil and soot as a result of the largest oil spill in human history. Plant life was affected through 1995. Since oil from the spill continues to seep into the ground, human drinking water may continue to be affected in the future.

10. Deepwater Horizon Oil Spill

Deepwater Horizon offshore drilling unit on fire — Image Source: Wikipedia

The largest maritime oil spill in human history, this man made environmental disaster on April 20, 2010 killed 11 people and dumped 4.9 million barrels of crude oil in the Gulf of Mexico. Cost-cutting measures by the British Petroleum (BP) company that owned the Deepwater Horizon oil rig, the rig’s operator Transocean, and the contractor Halliburton led to neglect of equipment and unsafe working conditions. This resulted in an explosion and subsequent oil spill. BP officials pleaded guilty to 11 counts of manslaughter. The company was also temporarily banned from contracts with the U.S. government.

The Bottom Line

These disasters remind us that not only are human beings quite fragile, but our earth is fragile as well. Wildlife and water sources can easily become contaminated due to our activity. If we want everyone on our planet, human or otherwise, to live long, healthy lives, we’ll have to be better caretakers than this.

The 5 Nuclear Waste Disposal Methods

Nuclear energy is commonly used in areas around the world today because it is a cost-effective way to produce a considerable amount of energy necessary for basic functions. Some medical facilities also produce this type of waste. While there are several nuclear waste disposal methods used by countries around the world, the issue of disposing of this incredible amount of waste is a growing concern for a justified reason.

By understanding more about current nuclear waste disposal methods, you may be able to see where the issues lie with some of the disposal methods currently being used.

1. Waste Remains On-Site at Power Plants

nuclear waste being stored at THORP processing plant — THORP Fuel Storage (Image Source: World-Nuclear.org)

Altogether, approximately 2,000 to 2,300 tons of radioactive nuclear waste are generated at energy plants around the world. When you are exploring the various nuclear waste disposal methods available, it is important to note that the waste is typically described as being either high-level waste or used fuel waste.

This waste may be in a solid or liquid form, and there are also waste products with low or intermediate levels of radioactivity. One of the more common nuclear waste disposal methods available for the high-level waste is to simply store the waste on-site at the power plants. This is done when there simply is no other reasonable method available for dealing with highly toxic waste products.

Special chemicals are usually used to pull uranium fuel out of specialized rods at nuclear power plants. As the chemicals extract the uranium from the rods, toxic liquid waste is generated by the chemicals. In addition, used rods are another form of waste.

Approximately 29,000 tons of used rods are currently in the world, and many of these sit in cooling pools located on-site at the nuclear power plants. This is not a long-term solution for dealing with this waste, however. This is because the available space on-site at various nuclear power plants is very limited.

More than that, the radiation can seep into the liquid in the ponds, and this could potentially contaminate ground water. You can see that this type of disposal method for dealing with nuclear waste is simply not ideal.

2. Waste Is Buried in a Landfill

one of the most common nuclear waste disposal methods is to bury it in a landfill — Nevada Radioactive Waste Dump (Image Source: Emaze)

When you are looking at the many nuclear waste disposal methods, it is also important to note that some waste actually makes its way to landfills, and this may include landfills that are located close to your home. Low-level radiation waste is usually compacted tightly or otherwise burned.

After one of these methods is applied to the waste, it is usually transported to a landfill. It simply sits in the landfill along with other types of waste that finds its way to landfills. This creates some level of radioactivity at these landfills, and some people are concerned about how this waste is impacting the environment.

For example, some birds may consume waste products at landfills, and pollution can also enter the air and water supply through the landfills.

3. Waste Is Solidified and Buried at a Deeper Level

underground disposal of nuclear waste — Underground Nuclear Waste Disposal (Image Source: Flickr)

Some nuclear reactors also create an intermediate-level of waste that requires more specialized handling. For example, this type of reactor waste typically must be solidified before it can be dumped in a landfill. It most commonly is turned into bitumen or concrete.

This solid waste material is then taken to a landfill for disposal. Generally, it must be buried deeper in the landfill and requires special handling. Nonetheless, some level of toxic radiation can still seep into the environment as a result of this type of waste handling method.

4. Waste Is Sealed and Stored in Approved Locations

Another common option for nuclear waste disposal methods relates to storing the material in off-site and approved locations. There are several locations across the country and beyond that are licensed for storing this type of waste, but many people have issues with these facilities being located close to their home or workplace. After all, issues related to earthquakes and other factors can create a serious risk of radiation exposure.

There are various types of storage facilities in the United States to handle different types of nuclear waste. For example, a facility in Barnwell, SC accepts waste from nuclear reactors. An Andrews County, Texas facility accepts compact waste. There are also other facilities located in Utah and Washington.

These facilities typically use either horizontal or vertical storage containers, and these containers are usually located above ground. While steps are taken to keep them properly maintained and in good condition, the reality is that the Fukushima Daiichi nuclear disaster issue caused by an earthquake and subsequent tsunami is a prime example for the reason for concern regarding nuclear waste and how it is handled.

5. The Controversial Space Disposal

Another method of disposal for nuclear waste is known as space disposal. With this type of method, the nuclear waste is solidified. After it has been solidified, it is launched into the earth’s orbit. Then, it is sent beyond the orbit. This option is rather expensive, but it solves the problem of an increasing amount of nuclear waste being stored on the planet.

When the waste has been permanently removed from the planet, natural disasters and other related issues are not a concern. However, some opponents of this type of plan are concerned about the possibility of the space vehicle or rocket that is being used to transport the waste potentially exploring en route. The effects of this type of disaster are unknown and worrisome.

Summing Up

Many people unfortunately assume that all of the waste being generated by nuclear activities worldwide is properly being disposed of. However, you can see that waste is not always eliminated at all. Instead, it is simply stored on-site or in an approved off-site location.

This means that much of toxic waste in the world is growing at a rapid pace rather than being eliminated it. This is a worrisome fact and we can only hope of discovering new methods of disposal soon.

Where Do Sinkholes Occur and How Do They Form?

Sinkholes are one of the many terrifying disasters of nature. Unpredictable and sometimes deadly, they seem to swallow homes and roads without discretion. You see devastating stories about them on the news all the time, but how much do you know about sinkholes? What exactly are they? Where do sinkholes occur? Is there anything you can do to protect yourself from them? Let’s find out!

What Are Sinkholes?

A sinkhole is a large depression in the ground that occurs as a result of underground dissolution and erosion of limestone and other carbonate rocks. Most of the time they actually form slowly, but some sinkholes appear suddenly and unexpectedly after a long process of erosion underground. Sinkholes have several alternate names, including cenote, swallet, and doline.

Where Do Sinkholes Occur?

Great Blue Hole sinkhole — The Great Blue Hole (Image Source: Flickr)

So, where do sinkholes occur? The answer is that they can and do appear all over the world; there are sinkholes on every continent and even under the ocean (the Great Blue Hole).

What Factors Make an Area Prone to Sinkholes?

Where do sinkholes occur within a region? There are a few factors that make a sinkhole more likely to develop. Sinkholes are most likely to occur in what is known as a karst landscape. A karst landscape is a stretch of terrain composed of large amounts of soluble minerals such as limestone. The land in Florida is mostly composed of limestone, which is why that state has many problems with sinkholes.

Where do sinkholes occur in the ocean? Just like on land, ocean sinkholes tend to occur in areas with a lot of soluble sedimentary rock. Some notable underwater karst landscapes are found off the coast of Belize, the Bahamas and the Yucatan Peninsula.

The deepest underwater sinkhole in the world, which is named Dragon Hole, is found in the South China Sea. In 2016, it was estimated to be 987 feet deep.

The second-deepest underwater sinkhole is Dean’s Blue Hole in the Bahamas, which is estimated to be 663 feet deep.

Oceanic sinkholes are often referred to as blue holes because they appear as a dark blue circle that contrasts with the lighter-colored water around them. Blue holes fascinate biologists because of the rare bacterial life forms that survive in their oxygenless depths.

How Do Sinkholes Form?

Sinkholes can form as a result of either natural or artificial processes or a combination of both. There are three types of nature-derived sinkholes: dissolution sinkholes, cover-subsidence sinkholes, and cover-collapse sinkholes.

Dissolution Sinkholes

The formation of dissolution sinkholes begins when acidic rainwater seeps through the ground and dissolves soluble rock (usually limestone) beneath the surface. This creates a gap in the sediment layers under the earth, weakening the foundation. The ground eventually collapses into the gap, resulting in a sinkhole. Though dissolution sinkholes are considered to be nature-derived, human pollution indirectly contributes to their formation by causing acid rain.

Cover-subsidence Sinkholes

Cover-subsidence sinkholes form much more slowly than other types of sinkholes. Like dissolution sinkholes, they mostly occur in limestone-rich karst landscapes. The difference is that cover-subsidence sinkholes involve sand sinking into the ground instead of acid rain. The sand siphons into cracks and gaps in the rock layers below. Over time, this forms a sinkhole in the ground. Where do these sinkholes occur? They mostly form in karst landscapes with sandy, granular soil on the surface.

Cover-collapse Sinkholes

Cover-collapse sinkholes appear rapidly. Where do these sinkholes occur? Whereas cover-subsidence sinkholes occur in sandy areas, the cover-collapse variety tends to show up in areas where there is copious clay in the topsoil. This type of sinkhole, like the others, begins with the dissolution of rock deep underground. In this case, the clay-rich topsoil holds out for a long time before collapsing. A huge gap appears beneath the surface, forming a sort of arch underground. When the arch collapses, the results are devastating.

Man-made Sinkholes

Sinkholes with man-made causes are most often the result of groundwater pumping, which can affect water drainage patterns deep beneath the soil. In 2013, a small sinkhole opened up in San Francisco because an aging sewer system exploded. A similar incident occurred in Florence, Italy in 2016 when an underground water pipe exploded and created a sinkhole. Above-ground construction can also pose a sinkhole hazard if the building materials place too much pressure on vulnerable tracts of land.

How Can You Protect Yourself from Sinkholes?

In areas that are known to be high-risk for sinkholes, professional geologists should be consulted before buildings are constructed. Buildings can sometimes be reinforced with special piers that are screwed into the ground to stabilize them. Another reinforcement technique is to use chemical grouting. This involves injecting certain chemicals into the sediment. The grouting fills gaps in the soil and strengthens it.

Sinkholes can be very difficult to predict. Signs tend to be subtle: plants dying due to loss of groundwater, development of new ponds or puddles, failure of windows to shut correctly, etc. If the land around your house starts to sink, it is recommended that you evacuate as quickly as possible and notify the building inspection department of your town. Insurance may cover damages caused by the sinkhole, especially in areas where sinkholes are a common occurrence.

Summing Up

To recap, a sinkhole is a depression that forms in the ground as a result of the dissolution of rocks under the earth’s surface. There are several different types of sinkholes, and they can appear both on land and under the ocean. They occur all over the world, but they tend to happen most often in karst landscapes.

Sinkholes can be slow-forming or sudden and come in a variety of sizes. Damages can be offset by consulting with geologists, reinforcing building foundations, and injecting grouting chemicals into the soil.