Mud slides or Rock slides in your Journey Management Program

In your Journey Management Program at work or in your workplace safe work procedures have you covered MUD AND ROCK SLIDES, just like in British Columbia AGAIN, there is another ROCK/MUD slide closing highway number one in Canada and REAL WORKERS in the area are at or near this location

Landslides occur when masses of rock, earth, or debris move down a slope. Debris flows, also known as mudslides, are a common type of fast-moving landslide that tends to flow in channels.

What causes landslides and debris flows

Landslides are caused by disturbances in the natural stability of a slope. They can accompany heavy rains or follow droughts, earthquakes, or volcanic eruptions. Mudslides develop when water rapidly accumulates in the ground and results in a surge of water-saturated rock, earth, and debris. Mudslides usually start on steep slopes and can be activated by natural disasters. Areas where wildfires or human modification of the land have destroyed vegetation on slopes are particularly vulnerable to landslides during and after heavy rains. Perhaps the most common reminders of landslide risks are those "Watch For Falling Rocks" highway signs. Although "sliding rocks" is more apt, very few get to see a land slide. Occasionally we see small rocks or debris on the pavement, but a large size slide usually starts with such small incidents. Visually, a landslide resembles a snow avalanche, only with a louder rumbling noise, and is capable of generating enough force and momentum to wipe anything in its path.

There are three basic types of mass wasting:

Falls - rocks fall or bounce through the air

Slides - rock and/or sediment slides along Earth's surface

Flows - sediment flows across Earth's surface

FALLS

While driving your vehicle through mountain country, such as parts of eastern California, you may have noticed signs such as: WARNING! ROCK FALL HAZARD.

Because weathering is an ongoing process, steep mountain slopes are constantly wasting away, often in the form of rocks falling and bouncing down slopes. Such falls can be triggered by freezing of water, the growth of plants (and their roots), earthquakes, or by people hiking on the slope. Rock falls occur in just a matter of seconds, so they are difficult (though fun) to observe. But, you can tell where rock falls occur on a mountain slope by looking for talus, a buildup of loose, angular rocks at the base of a steep slope.

SLIDES

Whenever a mass of slope material moves as a coherent block , we say that a slide has taken place. There are several types of slides, but one of the most common is a slump. A slump occurs when a portion of hillside moves downslope under the influence of gravity. A slump has a characteristic shape, with a scarp or cliff at the top of the slump, and a bulge of material (often called the toe of the slump) at the base of the slump. In the image shown below, see if you can spot the location of the scarp and toe of the slump.

FLOWS

We say that a flow has occurred if the material moving downslope is being transported as a very thick fluid (like a river of debris, rock, and/or soil), rather than as a coherent unit. Often, water is the primary transport agent for the flow.

Lahars

For sheer drama and destruction, you can't beat the mud flows that can occur when a volcano erupts. These flows are called lahars. After the Mount St. Helens eruption, for example, the heat of the volcanic products melted the snowcap. The resulting liquid water rushed down the volcano flanks, incorporating debris as it progressed. The damage to forests and humans was extensive.

Health threats from landslides and debris flows

In the North America alone, landslides and debris flows result in 25 to 75 deaths each year. The health hazards associated with landslides and mudflows include:

• Rapidly moving water and debris that can lead to trauma;
• Broken electrical, water, gas, and sewage lines that can result in injury or illness; and
• Disrupted roadways and railways that can endanger motorists and disrupt transport and access to health care.

What areas are at risk

Some areas are more likely to experience landslides or mudflows, including:

• Areas where wildfires or human modification of the land have destroyed vegetation;
• Areas where landslides have occurred before;
• Steep slopes and areas at the bottom of slopes or canyons;
• Slopes that have been altered for construction of buildings and roads;
• Channels along a stream or river; and
• Areas where surface runoff is directed.

What you can do to protect yourself

Before intense storms and rainfall

• Assume that steep slopes and areas burned by wildfires are vulnerable to landslides and debris flows.
• Learn whether landslides or debris flows have occurred previously in your area by contacting local authorities, a county geologist or the county planning department, state geological surveys or departments of natural resources, or university departments of geology.
• Contact local authorities about emergency and evacuation plans.
• Develop emergency and evacuation plans for your family and business.
• Develop an emergency communication plan in case family members are separated.
• If you live in an area vulnerable to landslides, consider leaving it.

During intense storms and rainfall

• Listen to the radio or watch TV for warnings about intense rainfall or for information and instructions from local officials.
• Be aware of any sudden increase or decrease in water level on a stream or creek that might indicate debris flow upstream. A trickle of flowing mud may precede a larger flow.
• Look for tilted trees, telephone poles, fences, or walls, and for new holes or bare spots on hillsides.
• Listen for rumbling sounds that might indicate an approaching landslide or mudflow.
• Be alert when driving. Roads may become blocked or closed due to collapsed pavement or debris.
• If landslide or debris flow danger is imminent, quickly move away from the path of the slide. Getting out of the path of a debris flow is your best protection. Move to the nearest high ground in a direction away from the path. If rocks and debris are approaching, run for the nearest shelter and take cover (if possible, under a desk, table, or other piece of sturdy furniture).

DURING

If inside a building:

• Stay inside.
• Take cover under a desk, table, or other piece of sturdy furniture.

If outdoors:

• Try and get out of the path of the landslide or mudflow.
• Run to the nearest high ground in a direction away from the path.
• If rocks and other debris are approaching, run for the nearest shelter such as a group of trees or a building.
• If escape is not possible, curl into a tight ball and protect your head.

Areas That Are Generally Prone To Landslides

• On existing landslides, old or recent
• On or at the base or top of slopes
• In or at the base of minor drainage hollows
• At the base or top of an old fill slope
• At the base or top of a steep cut slope

Areas That Are Generally Safe From Landslides

• On hard, non-jointed bedrock that has not moved in the past
• On relatively flat-lying areas away from slopes and steep river banks
• At the top or along the nose of ridges, set back from the tops of slopes

Features That Might Be Noticed Before Major Landslides

• Springs, seeps, or saturated ground in areas that have not typically been wet before
• New cracks or unusual bulges in the ground, street pavements or sidewalks
• Soil moving away from foundations
• Ancillary structures such as decks and patios tilting and/or moving relative to the main house
• Tilting or cracking of concrete floors and foundations
• Broken water lines and other underground utilities
• Leaning telephone poles, trees, retaining walls or fences
• Offset fence lines
• Sunken or down-dropped road beds
• Sudden decrease in creek water levels though rain is still falling or just recently stopped.
• Sticking doors and windows, and visible open spaces indicating jambs and frames out of plumb

After a landslide or debris flow

• Stay away from the site. Flooding or additional slides may occur after a landslide or mudflow.
• Check for injured or trapped people near the affected area, if it is possible to do so without entering the path of the landslide or mudflow.
• Listen to the radio or TV for emergency information.
• Report broken utility lines to the appropriate authorities.