meanwhile Millions of Americans take vacations Many people who flock to the beach every year for the sun, sand and sea may not realize just how dangerous digging holes in the sand can be.
In February 2024, 7-year-old girl dies A hole about 5 feet (1.5 meters) deep that she and her brother had dug in the sand collapsed on her, burying her alive.
As Coastal Science Researcher Having studied the beach for many years, I was called in to assist in the investigation of the girl’s death. After the hole in the sand collapsed, many people nearby tried to rescue the girl, but the local firefighters A few minutes after the incident – It’s too late to revive the victim.
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Digging a hole in the sand may seem harmless, but if the hole is deep and a person falls in, it can be very difficult to escape. In fact, research shows More people die Suffocation from being buried in sand is more likely to result in death than a shark attack.
Sand Foundation
Sand isn’t actually a type of material; it’s a size category of material. from Diameter 0.0025 to 0.08 inches (0.06 to 2 millimeters). Sand type It depends on the materials it is made of. Quartz SandCoral sand, made of silicon dioxide, is the most common type of sand found on beaches, except on tropical coasts where you will find coral sand beaches made of calcium carbonate.
Materials coarser than sand are not soft to the touch. You can’t build a sturdy sand castleSilt and clay are finer than sand and make the water cloudy, so they are commonly called mud.
The weight of sand depends on the material it is made of. Quartz Sand Beaches with very white sand weigh about 90 pounds per cubic foot when dry.
However, most beaches contain a mixture of minerals that give the sand its tan or brown appearance. The minerals that make the sand black are much heavier, with most beach sand weighing up to 130 pounds per cubic foot when dry.
Dry, loose sand grains form mountains with an inclination angle of about 33 degrees. Angle of reposeThe angle of repose is the steepest angle at which a pile of grain remains stable. Friction The strength between each particle determines its stability.
Sand is more stable when wet. surface tension The force between the water and the sand grains keeps the pile of sand vertical, but when it dries, the surface tension disappears and the pile collapses.
So if you dig a hole on the beach, it will remain stable as long as the sand is moist. If the sand dries, the hole will collapse.
Sand is unstable
If the sand that makes up the hole dries out, or if a person stands close to the edge of the hole and adds extra weight, the sand hole will collapse and the heavy sand grains will fill all of the open space in the hole, leaving the trapped person with no air to breathe.
A skier caught in an avalanche holds up his hands Forming air pockets Snow is light, but when the sand collapses, it’s not so light.
It is very difficult to extricate someone from a collapsed hole in the sand because sand is heavy and unstable. As rescuers scoop out the sand to free the victim, the hole continues to collapse under the rescuer’s weight and fills with sand again. Approximately 3 to 5 minutes Rescue someone trapped in a sand pit before they suffocate.
When firefighters or other professionals rescue people from collapsed sand pits, they place a board across the pit so they can reach in and use tools to remove the sand without putting their weight directly on the edge of the pit.
Experts recommend digging a hole no deeper than knee height of the shortest person in the group, with a maximum depth of 2 feet (0.6 meters).
To rescue someone in a collapsing sand pit, focus on exposing the mouth and removing the sand above the chest. If you can expose the mouth, Artificial respiration Other rescuers continue to dig up bodies.
Overcrowding a sand pit rescue can do more harm than good. Having two or three rescuers work in the area immediately surrounding the victim while others work to remove sand from the larger excavation area makes it easier for those in the middle to remove the sand. Those on the perimeter can remove sand from the central area using whatever is available, from buckets and shovels to beach chairs and bodyboards.
Case Study
Collapsing sand hole 31 people were killedIn a study conducted in the United States between 1997 and 2007, most were children and 87% were male. 21 more Sand pits were reported to have collapsed, but many survived, although they required CPR.
Victims of the Sand Pit Collapse Ages range from 3 to 21. The holes are generally They ranged from 2 to 15 feet (0.6 to 4.6 meters) in diameter and 2 to 12 feet (0.6 to 3.7 meters) deep. Digging, tunneling, jumping, or falling into the holes could all have unintentionally caused the collapse.
These collapses It can happen suddenlyand avoid holes in the sand even if they don’t seem dangerous to most people. Next time you go to the beach, be on the lookout for holes in the sand and make sure to fill all of them as soon as possible. Even shallow holes can injure someone who trips and falls.
Stephen P. LeathermanProfessor of Coastal Sciences Florida International University
This article is reprinted from conversation Published under a Creative Commons license. Original Article.
