All posts by Last Three

Redlands CA Preparedness

 

I chose Redlands, California to review the Hazard Mitigation Plan (HMP). Its a little town founded in 1860 during the Califonia citrus boom.  There is a bunch of really cool architecture here and citrus that make the city unique. It took one google search and clicking on the city’s website. There is a page full of helpful info to the local residents on all kinds of hazards.  Then I scrolled down and found the HMP.

I believe the community is well prepared for some hazards but not all hazards. The city has put significant effort into mitigation efforts from a possible flood from the Santa Ana River. They have built levees and several diversion culverts to protect the city from high water levels or flash flooding.

The city could inprove their protection of the bridges in the San Timatao Canyon. This is one of the ways in and out of Redlands but has to cross a small creek. The bridges are all built from old railroad cars sometime in the 50’s. This is a major corridor and could use more appropriate infrastructure for being built on a fault line.

I feel like Redlands is trying to be prepared has taken significant steps in doing so.

Preparedness and Water

When reviewing the FEMA independent study information it discussed Individual and home preparedness. Most people believe that the government will be there to help right away. This is obviously incorrect. We have taken some small steps to help us be better prepared in our home.

Living in southern California we face the real threat of a major earthquake. Water is moved (stolen) from Northern California and our neighboring states and moved through massive aqueducts down to southern California across the San Andres fault (SAF).   It is estimated that 70% of Californians will be out of water should a 8.0 earthquake strike along the San Andres fault.  That means 22 million people are one earthquake away from being totally cut off from a domestic water supply.  In 1857  a earthquake caused a surface rupture near Fort Tejon California ( Just north of LA) that moved the surface nearly 30′ in 120 seconds.  As you could imaging this would cause complete dissection of any aqueduct.

So… I chose to add to our emergency water storage.  We had one 55 gal and 30 gal water barrel. I added a second 55 gal water barrel nearly doubling our supply. I got the barrel at a local tack and feed store where they cut used barrels to make in to feed bins. The barrels have been previously used to hold commercial food products. The barrel stored low sodium soy sauce in it previous life.

They come well washed but  we wash them with a little dish soap and bleach water solution then a sponge screwed to a dowel.  After rinsing it out well we moved it in place next to the first one and filled it up.  We added unscented household bleach to keep the water sanitized as per the FEMA  and CDC recommendation.

FEMA recommended 1 gal per person per day in the home. This was for drinking. So we are counting on 3 gal per person per day. This included drinking, dishes, and personal hygiene.  There are 5 of us in our home so this will give us a little over 9 days of water.  Not much I know but its better than nothing. I think my goal will be to double my storage again to have two weeks worth of water.

 

And a cool article I found why researching earthquakes and water supply’s. 

Social Media

The use of social media looks to be helpful in reaching the masses in a short amount of time. The article I found talks about the federal governments use of social media during some of the more recent disaster and the challenges that are presented with that. Some of the Pro’s would be the ability to communicate with greater speed and in a first-hand form. Traditionally the entity that was managing a disaster would have to develop the message and depend on formal media to help push that message. There are delays with this process and its kind of like the telephone game where the message’s intent may be lost by miss interpretation. Also, things like the news cycle can delay the when the message is pushed and how much they focus on the message.  Social media can allow for a more real-time approach to the use of shorter higher priority message’s.

The cons to the use of social media are the lack of control over non-official posters. Often people post what they have heard will little or no vetting of the information. Or worse people pose as official sources and publish misinformation. Social media often can propagate rumors that are difficult to directly address by the public information officers (PIO’s) because you know how correcting someone online can go. The correction of rumors is done indirectly through the next cycle of messaging.

 

https://www.scientificamerican.com/article/how-social-media-is-changing-disaster-response/

 

 

Resources for the1992 Landers Earthquake

“1992 on the streets of LA where were you”

 

1992 was a year where many events that would shape the state and culture of California.  The LA riots and the Landers earthquake all within a few months. The Landers earthquake was centered to the sparsely populated area of Yucca valley. There was broken windows, partially collapsed buildings. The earthquake did little damage to the heavily populated San Bernardino valley just 40 miles to the South West. The damage there were mostly items knocked from shelving and broken windows.  The LA riots were just a few weeks later and did much more damage.

My favorite link is probably the story the”Californian blog spot” because it highlights the science behind the earthquake and a little on the local impacts. What I wish I could have found or learned was why the 1994 North ridge earthquake was so much more destructive than the Landers. They are relatively close ( when you consider the size of California)

 

http://thesoutherncalifornian.blogspot.com/2015/06/seven-facts-about-landers-earthquake.html

 

https://pubs.usgs.gov/gip/earthq3/safaultgip.html

 

https://blogs.agu.org/tremblingearth/2012/06/28/landers-20/

 

https://www.insidetheie.com/landers-earthquake

Case study 2 week 2

I played the stop disaster game for earthquakes but failed the three times I played. I want to say that something is wrong with the game. I met the objectives all three times but it said I still failed. I found it better to build new than to retrofit the old homes. the price of building new vs retrofitting was only $200 different and I could house more people in a newer home.

 

I don’t know how others did but my best score was a 0! I don’t think that’s very good for living in the earthquake-prone state of California.

Landers Earthquake

Pacific and North American plate boundary

Lander Earthquake

 

The Lander earthquake was the largest earthquake to hit Southern California in 40 years. Centered in the Mojave Desert, approximately 120 miles from Los Angeles, the earthquake caused relatively little damage for its size.

I chose this event because I live in California and can remember the event. This struck approximately 70 miles north of where I currently live. I can remember the damage that it caused in the local mountains. I had family that was up camping near Big Bear and were stranded for several days until the rock slides could be cleared from the highway.

I would like to learn why a relatively large earthquake caused relatively little damage to its surrounding communities. I would like to learn what faults were involved in the event and how these faults have shaped our local landscapes.

 

The nearest plate boundary is the transformational boundary between the Pacific and North American plate. The Boundary sits approximate 50 miles south-west of the epicenter of the Lander quake.  The Lander quake was very shallow at less than a tenth of a km deep (.06mi). As the Pacific plate grinds its way northward against the North American plate pressure builds along the plate boundary. When an undetermined amount of pressure forms the plates slip past each other causing earthquakes and fault ruptures near the epicenter.

The earthquake ruptured 5 separate faults: Johnson Valley, Landers, Homestead Valley, Emerson, and Camp Rock faults. The total rupture length was roughly 85km (53 mi), and the faults slipped from 2 meters (6 ft) to a maximum of 6 meters (~18 ft).

Most of the damage occurred to transportation infrastructure and power lines. The area near the epicenter was sparkly populated and California has had strict building codes long before the quake helping to minimize the damage to homes.

Initially, it was reported that there were several aftershocks. Later it was reported that the other local quakes were not an aftershock of the Landers Earthquake. Rather, that the preceding earthquakes in the San Bernardino Mountains was a part of a “regional earthquake sequence,” according to the United States Geological Survey (USGS)

 

Oso Landslide

 

Geologists say a landslide has caused this slope near Oso to drop 4 feet since Tuesday. (Washington State Department of Natural Resources)Oso Land Slide

 

My favorite source was number three on the list below. I think that is fascinating that though a little more investigation it was learned that this area has been prone to landslides for thousands of years. The original theories were that over logging of the mesa above the homes was a root cause. But the lidar takes some of the burden of the blame off the logging and back on to county planners. This disaster was a good example of how better building review could help save lives.

Another great article was the first on my list below. You can see the amazing resilience of people and how positive they can be finding the good out of all the bad that happened. It is inspirational to me. However, it can also help us understand how people can rebuild in the same flood plane time and time again. People believe that it was a “freak” event isolated in time. They don’t see that it is a pattern from the geologically unstable soil and debris left by a glacier.

 

  • Oso Mudslide: Residents Remember Tragedy One Year Later https://www.nbcnews.com/storyline/deadly-mudslide/everyone-came-together-residents-remember-oso-mudslide-one-year-later-n327931

 

  • Oso landslide hit fast, hard and with no warning                 https://www.usatoday.com/story/news/nation/2014/03/28/oso-landslide-seismic-records-two-slides-no-warning/7019249/

 

  • New analysis shows Oso landslide was no fluke                  https://www.seattletimes.com/seattle-news/science/new-analysis-shows-oso-landslide- was-no- fluke/

 

  • State investigates landslide near Oso; some residents evacuate  https://www.seattletimes.com/seattle-news/environment/landslide-near-oso-is-slow-                                   moving-washington-state-investigates-as-residents-evacuate/

Image: Oso Mudslide

Stop Disaster Wildfire

Since my hazard was landslides and there was no landslide game I wanted to try my hand at preventing a wildfire (given my background).  Let me say that I found the game harder than it seemed in real life. I chose the Australian outback option thinking it would be like California where I work and live.  I put significant effort in to remove the dead trees and grass from around the homes and infrastructure.

The mission of the game was to build a shelter for enough people and to “protect the water towers”. I cleared brush and upgraded the towers with the protective features and they still burned.  Guess I am not as good as I thought I would be. The second game my score was much higher (46,000) but I still failed the mission.

Things that rang true about the game was the need for distance from a structure and vegetation. Building in areas that are less prone to the propagation of wildfire (I.E. slopes and canyons) seemed to help and using less flammable decorative landscaping.

Mitigation of Landslides

The methods that are used for mitigation are often building restrictions. The building of roads requires additional slope stabilization and drainage efforts. Roads may be closed during high snow seasons or preventative avalanches may be caused to control the areas of the slide.  Some common mitigations you see on the west coast is metal mesh netting placed over loose or unstable rocky areas above the roadway.  The used of tiered slopes is also common when heavy grading has been done leaving largely exposed slopes

 

Tiered slopes reinforcing areas of heavy grading.

Rockfall protection along highways.

Gravel wire mesh bank revetment erosion control - Stock Image

Slope support and drainage.

Avalanche protection over highway section prone to avalanches.

 

Cannon used to fire explosive charges to cause a controlled avalanche.

Oso Landslide

 

 

 

 

 

The Oso landslide was a massive landslide that killed at least 25 people on March 22nd, 2014. The slide destroyed over two dozen homes in Oso, Washington and it came without seismic warning.

I chose this slide because of the recent mudslide and debris flows here on the central coast of California. Although the cause of the sides is different. The sides in Santa Barbara California were the result of very heavy rain in a very short period of time over steep recently denuded soils from a wildfire. The Oso slide was due to long periods of continues rain beneath an over logged mesa. I also chose this event because it is a great normative example of how better planning and mitigations for a known hazard could have saved lives.

 

Oso Washington sits near a complicated system of plate boundaries and faults. This area is near where the Pacific plate if forcing a chunk of the crust is known as the Juan de Fuca plate under the North American plate creating a very seismically active area. The nearest plate boundary to Oso Washington is the convergent boundary where the Juan de Fuca plate subducts beneath the North American plate. However seismic activity is not the cause of the Oso landslide.

What caused the landslide was the result of glaciers that retreated more than 15,000 years ago, leaving behind an unstable mix of till, sand, clay and lake sediments. The valley floor is smooth and flattened by the alluvial flows that the river has helped to shape. The valley is bordered by the steep hillsides that are a transaction of the loose glacial sediments.

The main contributors to the event were the predisposition to soil failure and the steady rain for 45 days. The water saturated soil broke loose from the hillside and slid destroying a community of tract homes that were recently built. The slide spanned nearly a half mile in length and several hundred feet thick at the highest point of the debris. The initial slide lasted approx. 2.5 min and had several smaller slides as the face of the scarf continued to slough off.

What is fascinating is what was learned after the slide. The area was observed with LIDAR (the map at the top of the post)  and mapped several slides in the area over the last 5000 years. The research shows that a major slide like the Oso slide happens approximately every 140 years. The study also reveals that the landscape is much more fluid and is expected to continue to have slid all along the valley.