Focus Area 1: Physical Geography

Sinkholes are common where the rock below the land is limestone or other carbonate rock. Sinkholes occur naturally, where abundant rainfall is located, and the gravel beneath the soil is limestone. Sinkholes are formed erosion broken down by water and rain. Sinkholes are common in rocky areas.

One major way Connecticut got its shape was from glaciation. For example, glaciation formed Jobs Pond. Jobs Pond is a giant kettle hole, which is a depression caused by the impact of a massive chunk of ice, or a glacier. According to The Mystery Of Jobs Pond, geologists and hydrologists the water level rises and falls with the groundwater level in the area, because porous sand and gravel make up the bottom of the pond. A kettle hole is formed by a glacier, so glaciation formed Jobs Pond. Another landscape formed by glaciation is recessional moraines. A recessional moraine is a pile of rocks left behind when a glacier recedes, or moves back. As a glacier moves, it picks up rocks in a process called plucking. Then, as the glacier starts to melt, it recedes. As it does this it drops off rocks, forming a recessional moraine. Recessional moraines, formed from glaciation, are found all along the Connecticut shoreline.

In the book Tangerine, the author Edward Bloor, writes about the sinkhole that takes place at Lake Windsor. Portables 16-21 are sucked into the sinkhole with some of the students still inside them. Thankfully, Paul, Joey, and other kids, help haul out the students trapped inside the sinkhole. The students managed to get all of the kids out, and nobody had any serious injuries. After the sinkhole, the engineers blocked off everything within a hundred-yard radius, and nearly all of the high school’s football bleachers. Which meant that half of Erik’s audience was gone, because of the sinkhole.

When this occurs, water from the wetland buildup can seep into the ground and be stored as ground for aquifers.

Similar to a cave, a sinkhole begins by acidic water dissolving carbonate bedrock creating an underground void. If the void grows close enough to the surface, the structural integrity of the surface material will eventually give way and a sinkhole is formed. These depressions can range in size from a few square yards to over hundreds of acres. The depth of sinkholes can vary from shallow to hundreds of feet. Although there are nearly 16,000 verified sinkholes in the state, the MGS caution there are a great number which have not been reported or documented. Some sinkholes in Missouri are known to be a depth greater than 100 feet though no exact records concerning depths are maintained. Located in western Boone County, the largest known sinkhole in Missouri covers approximately 700 acres. If a sinkhole does occur, it is recommended that a registered geologist or professional engineer be consulted to assist in the stabilization of the sinkhole. Filling a sinkhole, referred to as remediation, generally consists of removing all soil materials down to the bedrock surface and filling it with size-graded material. Larger rocks should be used first with each successive layer consisting of gradually smaller grained material. Geotextile fabric covered by top soil will allow water

They are called transversal when pressure builds and the rock breaks the energy of the break

The United States Geological Survey (USGS, n.d.) defines a sinkhole as "an area of ground that has no natural external surface drainage--when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface." Sinkholes vary in size considerably: from a few feet in diameter and one foot of depth, to "hundreds of acres" wide and "more than 100 feet deep," (USGS, n.d.). Some sinkholes form naturally over time, but human intervention such as construction and development projects have been causing the rapid development of sinkholes in the state of Florida. These large-scale projects can have disastrous effects on the economy and environment, as well as public safety. Sinkholes are especially problematic when they occur suddenly, without warning, in urban areas (USGS, n.d.).

Sinkholes are pits in the ground that form where water gathers with no drainage. The water weakens the ground under the surface and any weight on the affected area will collapse the ground.

Within the state of New York, landslides are classified as the downward movement of a slope and materials under the force of gravity (New York State Hazard Mitigation Plan, 2008). This definition also includes: a wide range of ground movement, such as rock falls, deep slope failure, shallow debris flows, natural rock, soil or artificial fill (New York State Hazard Mitigation Plan, 2008). Depending on the size and location of the landslide, landslides can be dangerous (Hyndman and Hyndman 2014). There are three mechanisms that initiate landslides. One mechanism is too much water. When water is added to a slope, soil becomes saturated and pore water pressure increases causing a slope to slide. A second mechanism is cutting the toe and oversteepening of the base. Removal or addition of material at the bottom of a landslide increases steepness of a slope. A steeper slope is less stable, increasing the likeliness of a landslide to occur. The third mechanism is adding material to the top of a slope, this also helps creates steeper

They can be caused by several different events including the undercutting a slope, or wearing away at the base of a hill from underground, because of stream erosion, or heavy or lengthy rainfall, rapid snowmelts, quick changes in groundwater. Other causes are seismic activity from construction or earthquakes or placing to much weight at the top of a hill. Some types of soil, such as clay or silt, are more prone to landslides than others so you must always learn more about the local geology and use geological mapping to detect slope hazards before building. There are multiple types of landslides (ADD PICTURES OF EACH AND MOVE TEXT ACCORDINGLY) like a slide, parallel movement along weak planes, a creep, slow movement of debris over a long period, a slump, ground falling in on itself in some places and moving downhill, a topple, objects tumbling end over end, a fall, falling objects possibly caused by a stream undercutting a bank or cliff, a flow, a mass moving in a water like fashion downhill, or a torrent, which is a random rapid release of water and other material (BC Geological Survey of the B.C. Ministry of

Sinkholes however, appear all around the world, both naturally and due to human interference with the earth. While the process of erosion that leads

Gaps between two different sedimentary rocks, are called unconformities. These gaps usually happen when an old layer of sedimentary rock is covered by a new layer of sedimentary rock. They are called unconformities because they don’t conform the basic geological expectations. So, what are the expectations? The law of original horizontality states that layers of sedimentary rock called strata, should be laying down horizontally to the earth's surface, just like pages in a book. Where the layers mismatch and create a gap, that is called an unconformity.

A sinkhole, also called a swallow-hole, shakehole, swallet or doline, is a crater in the ground caused by a sudden collapse of the surface layer whether it is the street, a field, a suburb, city, or other area,. The causes of sinkholes consist of karst processes such as the chemical dissolution of carbonate rocks and suffusion processes. The formation of sinkholes involves the processes of erosion. Sinkholes develop due to surface drainage or running water. Though dry places are thought to have less water, sinkholes can develop in these areas as well as long as the correct conditions come into play. They can form from human activity as well like abandoned mines, pipelines and sewers. Sinkholes are most common in states such as Alabama, Florida, Kentucky, Missouri, Pennsylvania, Tennessee and Texas. Places with sandstone and quartzite terrains where the rock below the land surface is limestone or any other carbonate rock that can be dissolved by ground water. When the rock below the surface layer dissolves, spaces and caverns form underground. Sometimes it can take months or even years for these caverns to form completely before the ground becomes too weak and collapses suddenly.

The term ‘landslide’ includes all varieties of mass movements of hill slopes and can be defined as the downward and outward movement of slope forming materials composed of rocks, soils, artificial fills or combination of all these materials along surfaces of separation by falling, sliding and flowing, either slowly or quickly from one place to another. Although the landslides are primarily associated with mountainous terrains, these can also occur in areas where an activity such as surface excavations for highways, buildings and open pit mines takes place.

Landslides can occur virtually anywhere in the world, where climate, precipitation, bedrock and soil conditions and slopes are susceptible to failure. Landslides can occur under water too, along continental slopes and deep sea fans.