EOTW#10 – the 1967 Fairbanks, Alaska flood

I guess it’s time to do a EOTW closer to home (although I know some of you are all over the country!). The 1967 flood happened on the Chena River in Fairbanks during Augustin 1967. During July 1967, the Fairbanks area received almost twice the normal amount of rain as 3.32 inches fell. During August, the rain did not let up and another 3.42 inches fell within a 24 hour period between August 11 and 13. In total August 1967 experienced 6.2 inches of rain – almost triple the normal amount for August.  As a result, the Chena River received far more water than usual and passed its flood stage. At the time, there was no stream gauging equipment on the Chena upstream of Fairbanks so the people and scientists did not know how bad the flooding would be.  Flooding by August 14th was bad and many people evacuated. About 7,000 to 8,000 sheltered at UAF, which given its elevation was out of the flood waters.

Although Fairbanks is situated in a flood plain, we have not experienced flooding of this magnitude since. Read the following articles, and answer the questions below:

https://www.encountersalaska.org/fairbanks-flood-1967/

https://www.adn.com/opinions/2017/08/15/fairbanks-recalls-the-great-flood-that-changed-everything/

  1. Why have we not had such severe floods since 1967?
  2.  Briefly describe at least one positive outcome that emerged as a result of the flood damage and losses.

Optional – If you live in Fairbanks, I encourage you to take the Flood Tour set up last summer in commemoration. See below for the map!

https://www.weather.gov/aprfc/FairbanksFlood1967

More photos from the flood:

http://vilda.alaska.edu/cdm/ref/collection/cdmg11/id/35056

EOTW# 9: The St Francis Dam Disaster

For this week, we are going to explore a human+geology caused disaster to bring awareness to the issues we can have when dealing with large-scale infrastructure as well.

On March 12th 1928 at approximately 11:58 PM, the St Francis dam om California failed, resulting in a ~5.5 hour-long flood through the Santa Paula-Ventura area in California. More than 400 people died during the resulting flood. The St Francis dam was built in San Francisquito canyon to hold water that was running through the California Aqueduct from the Owens Valley. The dam was approximately 205 feet high  and spanned 1225 feet along its crest and 150 feet at its base across a narrow spot in the valley and canyon. The dam was 160 feet thick. The dam construction was overseen by William Mullholland, who at the time was one of the architects of the massive growth of Los Angeles – made possible in large measure by the piping of water from the Owens Valley and other parts of California, to the growing and thirsty town. While he had worked on another dam (Mulholland dam), Mulholland was essentially a “self-taught” civil engineer. The dam failure is considered one of the worst civil-engineering disasters in US history. The failure was originally thought to have resulted from issues with the dam’s foundation. More recent work indicates that the ground beneath the dam also played a role, in the form of water-saturation re-mobilizing an old landslide structure (see quote below for more details*).

For this week’s assignment, read the following Smithsonian Magazine article that explains the history leading up to, during, and following the disaster and answer a couple questions: https://www.smithsonianmag.com/history/occasions-i-envy-dead-st-francis-dam-disaster-180954543/?page=1

1) How much water was released during the dam failure?

2) How were people downstream warned of the coming flood, once people realized what was happening?

3) Take a little tour in Google Earth in the region, by searching for St Francis Dam.  From your search, can you figure out how the water is now stored in this region to serve LA?

Related image

Photo from http://archive.signalscv.com/archives/146899/

*”Although opinions vary, more recent and more thorough investigations assign the ultimate failure mode to weakening of the left abutment foundation rock due to the saturated condition created by the reservoir which essentially re-activated a large landslide that combined with a destabilizing uplift force on the main dam caused failure to initiate at the dam’s left end. In quick succession as catastrophic failure was occurring at the left end, the maximum height section tilted and rotated which destabilized the right end of the main dam causing catastrophic failure at the right end as well.” (http://damfailures.org/case-study/st-francis-dam-california-1928/)

Additional Resources and Sources of information for the post:

http://waterandpower.org/museum/St.%20Francis%20Dam%20Disaster.html

https://scvhistory.com/scvhistory/stfrancis.htm

http://damfailures.org/case-study/st-francis-dam-california-1928/

EOTW #8 Building Resilient Communities

The EOTW for this week is not so much an event, but a tool to get you all thinking beyond your Case Studies for what comes next in the course. Units 7 and 8 will focus on societal implications and issues and preparedness. One of the key parts of being a prepared community is resilience. Resilience is really a mitigation tool. Once a community recognizes which areas it has that are vulnerable to a particular disaster or disasters, it can make the decision to reduce the risk by increasing resilience. The word resilience means to be “able to withstand or recover quickly from difficult conditions.” (from the google dictionary). The two parts to this equation are to be able to withstand a disaster, as well as be able to recover quickly. It turns out that the National Institute of Standards and Techonology (NIST) has a program to help communities develop resilience to disasters. To get our brains thinking beyond the disasters we studied for Units 5 and 6, read the article by NIST and answer the questions below:

https://www.nist.gov/topics/disaster-resilience/helping-build-nation-resilient-communities

  1. Describe one new thing you learned from this article that shows that we are working in our country to improve our resilience
  2. Can you take what you learned and think of one way that your own community might be able to increase its resilience to a likely future disaster?

EOTW #7 The Great Flood of 1862

During December 1861 in California, it started raining and raining and raining and snowing in the mountains. After approximately two decades of drought, it rained for approximately four months, depositing so much water that massive regions in California flooded. Large portions of the Central Valley flooded, and approximately 66 inches of rain fell on typically arid Los Angeles. The result was huge losses of cattle from the ranch lands (1/4 of the total head in the state), houses and buildings due to widespread, and often very deep, flooding.  Sacramento, the state’s capital, was submerged in water. Flooding was extensive over several western states, including Oregon and Arizona. The phenomena responsible is called an “atmospheric river”.  Just this week, an atmospheric river delivered significant rain to the already vulnerable regions around Santa Barbara and Ventura, resulting in renewed called for evacuations due to possible mudflows in regions impacted by the Thomas fire. For this EOTW comment assignment, read the first two articles below. I include the USGS website as another tool you can use to learn more about the potential for future mega flooding in the state, as well as maps and assessments of vulnerable populations. Then, answer the following questions:

1) What are atmospheric rivers? About how often do megafloods impact the California and western states regions?

2) Approximately how extensive was the 1861-62 event in terms of geography? (ie which states and countries were impacted)?

3) How well do you think the public is aware of the mega flood hazard, compared with earthquake hazards, in California and other western states?

http://www.noaa.gov/stories/what-are-atmospheric-rivers

https://www.scientificamerican.com/article/atmospheric-rivers-california-megaflood-lessons-from-forgotten-catastrophe/

https://geography.wr.usgs.gov/science/mhdp/arkstorm.html

EOTW #6 Earthquake Early Warning Systems

This event of the week is really more of a “monitoring and mitigation tool” of the week: the Earthquake Early Warning (EEW) system. This potentially life-saving tool has been in the news recently as the US government prepares the next budget. But, what is it exactly, how does it work, who would it help save, and where has it been used successfully? I think that it is important for us all to be aware of the science behind the EEW and to also be aware that there are countries that already have early warning systems and that they have already proven to be successful. So, for this week, I would like us all to learn more about the status of EEW in the US, how it would work, what type of seismic network is needed, and compare/contrast where we are in the stage of development versus other countries that already have this type of system operational.

  1. Read all the earthquake early warning system sections on the following webpage:  https://earthquake.usgs.gov/research/earlywarning/
  2. Briefly, how does the early warning system work?
  3. List the countries that currently have early warning systems in place (hint – the US does not yet have a fully operational version so should not be included in this list)
  4. See if you can find a recent example from the news where an early warning system alerted people ahead of an earthquake – how much time did they have to take cover? What type of alert was used (text, siren, combination?)

EOTW #5 – 2015 M8.3 earthquake in Chile

There have been a few recent hazardous events that could have been much worse. One of these is the 2015 magnitude 8.3 Illapel earthquake that struck 46 km offshore of Illapel Chile, about 177 miles north of the nation’s capital of Santiago. This earthquake caused a tsunami that traveled across the Pacific ocean, triggering tsunami warnings from Hawaii to Japan and to California. There is a really cool animation showing the propagation of the tsunami, which created a pattern of standing waves across the Pacific Ocean Basin about 24 hours later:

Although this event was truly a great earthquake and caused much greater shaking than the 2015 Nepal M7.9 earthquake, or the 2010 Haiti M7.0 earthquake, it resulted in about 10 fatalities. In contrast, about 8,000 people lost their lives during the Nepal earthquake and nearly 200,000 lost their lives during the 2010 Haiti earthquake.

Read the following articles, and answer the questions below:

Popular Science article on 2015 Chile earthquake and tsunami

New York Times Article on the 2015 Chile event

  1. Why did the Chilean event result in tremendously low loss of life compared with Nepal and Haiti?
  2. Approximately how many people were evacuated during the tsunami warning?
  3. Explain one reason why Chile is so well-prepared compared with other countries like Haiti and Nepal?

EOTW #4: The 2013 Rim Fire – WUI, Social Media, and Fire Supression

The Rim Fire started August 17, 2013 in the Stanislaus National Forest by a hunter who had started an illegal fire that got out of control. The fire burned more than 257,000 acres, and is currently the fourth largest wildfire in California history. It burned 11 homes, 3 commercial buildings, and 98 outbuildings. Hot temperatures, severe drought, and a long-term program of fire suppression in California helped fuel this enormous, intense wildfire event. These types of wildfires are becoming more frequent in the western US. A consensus appears to be emerging between scientists and wildfire experts that these wildfires are becoming more intense because of several things: climate change fueling drought and higher temperatures, leading to drier conditions; encroachment of urban areas into wildlands (the Wildland-Urban-Interface – WUI – is expanding); and a years-long policy of fire suppression (particularly because of the expanding WUI and landowners wanting protection from fires). Fire suppression and recent climate swings have resulted in a lot of overgrowth in the forests in the region.

There were a few issues surrounding this event that are worth exploring because they are relevant to other disaster events. One of the issues involved the spreading of false rumors over social media: https://www.theguardian.com/world/2013/aug/27/rim-fire-california-social-media-avoid

Decades of fire suppression and lack of funding for forest management has created regions that are overgrown, fueling faster spread of fires: https://www.livescience.com/39408-how-rim-fire-grew-big.html

For this EOTW, read the two articles linked above and answer the following questions:

1) Why did the fire grow extremely rapidly in the Stanislaus National Forest, but in  Yosemite National Park the fire did not grow or spread nearly as fast?

2) Do a quick search on google and find another disaster event that involved social media – briefly describe whether social media was a good source of information or was involved in spreading fear through untrue reporting.

 

EOTW #3 – 2017 was the costliest disaster year

 

I was looking for a wildfire disaster as the topic of the EOTW this week when I stumbled across an interesting bit of news from NOAA. The year 2017 cost more than $300 billion in disasters that occurred in the US.  From NOAA:

“In total, the U.S. was impacted by 16 separate billion-dollar disaster events including: three tropical cyclones, eight severe storms, two inland floods, a crop freeze, drought and wildfire.”

The next most costly disaster year happened in 2005 largely because of Hurricane Katrina. That year cost almost $215 billion in terms of damage from four hurricanes: Katrina, Dennis, Rita, and Wilma.

For this assignment, do the following:

1) Although it is long, I would like you all to read the summary from NOAA – https://www.climate.gov/news-features/blogs/beyond-data/2017-us-billion-dollar-weather-and-climate-disasters-historic-year

2) From this report, find out and write about which two types of hazards have been the costliest (e.g., wildfires, tornadoes/severe weather, tropical storms, inland flooding, etc).

3) Which disaster type has resulted in the most fatalities in the US between 1980 – 2017? Which is the second deadliest type of disaster?

4) Write briefly about one mitigation idea or solution you think could help reduce cost and loss of life from one of those types of disasters in the future.

EOTW #2: The 1964 Great Alaskan Earthquake

The Great Alaskan Earthquake of 1964 is the largest to have occurred in the US. This earthquake was a whopping M9.2! The scale of this type of “megathrust” earthquake is really difficult to comprehend – it disrupted land in Alaska over an area larger than the state of California – 185,000 square miles. (CA is 163,696 square miles in area). After a major geological event, geologists do a kind of “forensic” analysis afterwards with the goal of understanding it in as much detail as possible. The results are then translated to understanding when future earthquakes may be likely to happen, how to better map earthquake hazards in Alaska, as well as earthquake mitigation and monitoring efforts in the whole country. While devastating, the 1964 earthquake has allowed us to be better aware and prepared for future large earthquakes in the US (and even worldwide).

For this EOTW assignment, first watch the following ~11 minute long video by the USGS and then answer the following questions based on what you learned:

  1. What geologic phenomena specifically caused the tsunami that inundated Whittier, Alaska in 1964?
  2. How often have magnitude 9 earthquakes happened in the South Central Alaska region in the past 5500 years?
  3. Which Alaskan town was moved after the 1964 earthquake because it was built on unstable ground?
  4. Briefly describe the most interesting thing you learned from this video

 

EOTW #1 – The Magnitude 7.9 Kodiak Earthquake

The first Event of the Week assignment will focus on an event that truly was of this week! The magnitude 7.9 Kodiak earthquake happened early in the morning of January 23rd, shaking people awake across south central Alaska and resulting in a tsunami warning that prompted evacuations of many from coastal towns and cities. The earthquake has also sparked the interest of the media, and resulted in some fearful reactions because of other earthquakes and volcanic eruptions occurring around the Pacific rim recently.

Below are a couple of maps from the Alaska Earthquake Center content page about the event: http://earthquake.alaska.edu/magnitude-79-offshore-kodiak-evolving-content-page

This earthquake prompted tsunami warnings to go out to many along coastlines in the Pacific, including California. Tsunami can travel very fast, 500 MPH (about as fast as a commercial jet) so especially for local communities, timely warnings are critical. In this case, fortunately, only a very small tsunami resulted.  An interesting article by ABC News describes how difficult it is to issue timely warnings while scientists are still gathering data quickly and before they may have all the information they need: http://abcnews.go.com/Technology/wireStory/alaska-quake-shows-complexity-tsunami-warnings-52560219

 

For this assignment, do the following tasks and then make a comment to this post with your summary:

  1. Read about the science behind the earthquake from the USGS Earthquake Hazard Program: https://earthquake.usgs.gov/earthquakes/eventpage/us2000cmy3#executive
  2. What kind of earthquake fault produced the event? (Strike slip, normal, or reverse/thrust fault?)
  3. Why was there only a very small tsunami produced?
  4. Choose one of the three articles below and read it thoroughly. Then pick one thing new that you learned about geology, hazard assessment, mitigation (ie evacuation in this case) that you did not know before:

New York Times Article about the event: https://www.nytimes.com/2018/01/23/us/earthquake-tsunami-alaska.html

ADN article about evacuations: https://www.adn.com/alaska-news/2018/01/23/orderly-evacuations-prevailed-in-alaska-coastal-cities-after-7-9-earthquake-set-off-tsunami-alarms/

New York Times article about how difficult it can be to forecast tsunami: https://www.nytimes.com/2018/01/23/climate/alaska-earthquake-tsunami-forecast.html