LANDSLIDES
by Donna Singson Argawanon (Oh Donna Kim)
1. 1.Natural causes include: elevation of pore water pressure by saturation of slope material from either intense or prolonged rainfall and seepage. vibrations caused by earthquakes. undercutting of cliffs and banks by waves or river erosion.
2. 2.A major landslide occurred 4 miles (6.4 km) east of Oso, Washington, United States, on March 22, 2014, at 10:37 a.m. local time. A portion of an unstable hill collapsed, sending mud and debris to the south across the North Fork of the Stillaguamish River, engulfing a rural neighborhood, and covering an area of approximately 1 square mile (2.6 km2). Forty-three people were killed and 49 homes and other structures destroyed
2.1. 6.To achieve this result, some actions are required: Covering the land with impermeable membranes in order to prevent water infiltration in the landslide; Directing surface water sources away from the landslides; Draining ground water streams away from the landslides; Minimizing irrigation on the surface of the soil.
2.2. 11.The disastrous March 22 landslide that killed 43 people in the rural Washington state community of Oso involved the “remobilization” of a 2006 landslide on the same hillside, a new federally sponsored geological study concludes.
3. 5.Soil organisms are responsible, to a varying degree depending on the system, for performing vital functions in the soil. Soil organisms make up the diversity of life in the soil . This soil biodiversity is an important but poorly understood component of terrestrial ecosystems. Soil biodiversity is comprised of the organisms that spend all or a portion of their life cycles within the soil or on its immediate surface (including surface litter and decaying logs)
3.1. 9.A large landslide occurred in northwest Washington on March 22, 2014, leading to tragic loss of life and destruction of property. Landslide debris covered about 40 homes and other structures as well as nearly a mile of State Route 530. It also caused 43 fatalities in the community of Steelhead Haven near Oso, Washington.This event is commonly named the “Oso Landslide” in many official reports. It is also referred to as the “SR530 Landslide,” as named by Snohomish County and Washington State
3.2. 14.An accurate way of predicting landslides. ... A landslide can seriously injure or even kill people. Now, a new early warning system will be the first to employ geological data in tandem with the latest weather forecasts to provide a concrete warning in emergency situations.
4. 3.Local seismic measurement stations clearly show that the event happened with no warning and so quickly that victims in its path had little chance to run for safety. Even if it had been slower, there would have been nowhere safe to run — the slide area is almost a mile across.Shortcuts
4.1. 7.Along with continuous storms from early this year, the catastrophic floods , landslides have been threatening the livelihood and lives of many people. With a view to minimize the loss of life and property caused by floods and landslides, responsible authorities need to make clear warning about high-risk areas .
4.2. 12.However, some analysts point out that, at least in geological terms, this was a disaster waiting to happen. The quake resulted from a collision between the Indian and Eurasian seismic plates. Seismologists have found out that the Indian subcontinent is moving north at a speed of 45 millimeters (1.7 inches) a year under the Eurasian plate, thus building the Himalayan mountain rangeThis fault line runs along Nepal's southern border and the constant friction between the plates eventually unleashes an enormous amount of energy in the form of earthquakes. In fact, according to a report by Nepal's National Society for Earthquake Technology, the seismic records of the region suggest that a major earthquake occurs approximately every 75 years, with previous tremor of such magnitude striking the region in 1934. .
5. 4.Local seismic measurement stations clearly show that the event happened with no warning and so quickly that victims in its path had little chance to run for safety. Even if it had been slower, there would have been nowhere safe to run — the slide area is almost a mile across.
5.1. 8.Landslides cause property damage, injury and death and adversely affect a variety of resources. For example, water supplies, fisheries, sewage disposal systems, forests, dams and roadways can be affected for years after a slide event.The negative economic effects of landslides include the cost to repair structures, loss of property value, disruption of transportation routes, medical costs in the event of injury, and indirect costs such as lost timber and lost fish stocks. Water availability, quantity and quality can be affected by landslides. Geotechnical studies and engineering projects to assess and stabilize potentially dangerous sites can be costly.
5.2. 13.Monitoring is essential to predicting the behavior of landslides and forecasting which storms can trigger large numbers of landslides. Scientists in the USGS Landslide Hazards Program monitor selected landslides and hillsides in order to learn more about the physical processes that trigger landslides or control their mvement
6. 5.Soil organisms are responsible, to a varying degree depending on the system, for performing vital functions in the soil. Soil organisms make up the diversity of life in the soil . This soil biodiversity is an important but poorly understood component of terrestrial ecosystems. Soil biodiversity is comprised of the organisms that spend all or a portion of their life cycles within the soil or on its immediate surface (including surface litter and decaying logs)
6.1. 10.The negative economic effects of landslides include the cost to repair structures, loss of property value, disruption of transportation routes, medical costs in the event of injury, and indirect costs such as lost timber and lost fish stocks. Water availability, quantity and quality can be affected by landslides.