Interpretation Part Two: Example from the Classroom

Part one of this series focused on the role of naturalists as interpreters and described a lesson by Tracy Drake, Manager and Naturalist at the Madrona Marsh Preserve & Nature Center. Part two includes an example of interpretation presented by students in the California Naturalist Program at the Dominguez Rancho Adobe Museum.

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February 14, 2015

The Story of Karen, Sharon, & Aaron (aka Frank)

The class was divided into groups and told to roam the Rancho's grounds in search of a story. Once each group had developed their story, they were to give a brief presentation to the class. All of the groups did a spectacular job of finding an interesting subject and utilizing the tools listed in part one of this series on interpretation. One group gave a particularly memorable performance.

The first speaker introduced the group. "Hi, we're Karen, Sharon, & Aaron. Actually, he's Frank, but we thought we'd continue the rhyme." Humor in the first line; right away, they had our attention.  With each member of the group taking turns, they went on to describe their subject -- a floss silk tree (Chorisia speciosa). They told us that they had looked up information about floss silk trees and discovered that they are native to Brazil. Then they went on to describe the tree in rich detail, beginning with its location on the grounds and talking about its unique appearance. They described the spiny bark and theorized reasons for the tree to have adapted that defense mechanism. In contrast to the sharp spines, they described soft, cottony balls that were hanging from the branches. Bits of fluff had begun to fall from these balls, and the group passed some of it around the classroom so that we could all experience how it looked and felt. Like many plants, the group said, the floss silk tree has practical uses. Hummingbirds take bits of the soft fiber for nesting material. It also has industrial applications as filling for life preservers.*

Floss Silk Tree (Chorisia speciosa)

The group organized their presentation around a central theme of "Change at the Rancho." At the time, the floss silk tree was leafless. Aside from spines, its only decoration was the large, white seed pods. What would it look like in a few weeks or a few months? The hummingbirds would be using it for nesting material, but what other wildlife uses might it have at different times of the year? And change, they said, is not limited to this tree alone. Everything at the Rancho is in a state of continuous change. Aside from the truth of their statement, the theme also worked because it reinforced an idea from the morning's earlier activity (Bird Walk with Tracy Drake). During the walk, Tracy pointed out birds currently found at the Rancho and also predicted which birds we should expect to see at different times of the year according to when various trees would produce fruit.

Karen, Sharon, & Aaron (aka Frank) were successful in their presentation because they avoided giving a mere recitation of facts and used many of the tools available to interpreters including:

• Humor
• Knowing your subject matter
• Using technology for on-the-spot research
• Giving each person a part to play
• Invoking the senses (in this case sight and touch)
• Having a unifying theme
• Making it relevant
• Making it pleasurable
• Reinforcing learning in other areas
• Inspiring the audience to look deeper into the subject themselves

* According to Wayne's Word, an online textbook of natural history, the floss silk tree is in the family of trees called kapok. Fibers of kapok trees have a water-resistant coating and are also lighter in weight than cotton fibers. These attributes make them perfect for filling life preservers. In fact, life preservers filled with kapok can support 30 times their weight in sea water. Kapok fibers have also been used to fill mattresses, pillows, upholstery, and softballs.

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Time was set aside following the presentations for journaling in our nature notebooks. Inspired by Karen, Sharon & Aaron's presentation, I decided to visit the floss silk tree. When I arrived at the tree, I noticed that another member of the class had also been inspired to take a closer look. We chatted for a moment about the pieces of floss strewn about the grass and then separated to make our own observations.

Living in southern California, floss silk trees are a fairly common sight. Therefore, I thought I knew what to expect from this one. However, I was surprised by some of the details. Most surprising was the shape of the seed pods. They looked like a child's craft project, made out of cotton balls stuck together to form an ornament.

Seeing pieces of floss caught on the branches of a neighboring tree, I realized how appropriate the group's theme of change at the Rancho had been. In a few months, there might be nothing left of those seed pods, all of the floss having blown away or used for nesting material. A few signs of earlier stages of development were present. One desiccated fruit hung from the branches. Birds, most likely yellow-chevroned parakeets, had eaten it clean through, leaving a view from one side to the other.

A few strips of dried husk lay on the grass, indicating the way in which the fruit must split before dropping its cover to release seeds. I decided to return in a few weeks and see what further changes developed.

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March 7, 2015

The tree had been changing! The floss was no longer tightly packed into balls. Instead, it hung loosely and was dotted with seeds. I saw a hummingbird near one of the seed pods but did not observe it taking any floss.

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April 15, 2015

Most of the loose floss seen on my previous visit was gone. Now the seed pod looked something like a fur-covered hand with fingers hanging down. Some of these "fingers" had fallen to the ground. It was possible to pick one up and see its internal structure.

And yes! There it was -- a hummingbird gathering nest material! I happened to be in the right place at the right time and lucky enough to document it with a photograph.

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April 22, 2015

Our naturalist class is coming to an end, and I will have fewer opportunities to visit the Rancho. I know that the tree and the grounds will keep on changing whether I am there to see it or not. When I do visit, I will be sure to look at the floss silk tree and remember the presentation by Karen, Sharon, & Aaron (aka Frank).



References:

Drake, Tracy (lecture on interpretation, at the Dominguez Rancho Adobe Museum, California Naturalist Program, Rancho Dominguez, CA, February 14, 2015).

Atkin, Frank, Sharon Swonger, and Karen Thompson, "Change at the Rancho" (lecture at the Dominguez Rancho Adobe Museum, California Naturalist Program, Rancho Dominguez, CA, February 14, 2015).

"Plant Fibers," Armstrong, W.P., last modified last modified March 5, 2010, Wayne's Word, accessed April 22, 2015, http://waynesword.palomar.edu/traug99.htm

Interpretation Part One: Connecting with Your Audience

Early in the California Naturalist Program at the Dominguez Rancho Adobe Museum, Tracy Drake, Manager and Naturalist at the Madrona Marsh Preserve & Nature Center, spoke on the role of naturalists as interpreters. According to Tracy, interpretation is more than just spouting facts. Interpreters use facts to create meaning. They form connections between different parts of the environment, and between the environment and people. Often, they accomplish this by showing people aspects of the natural world that they might not have noticed otherwise. The most successful interpreters develop each lesson for a particular location and audience and organize their facts around a unifying theme. Referencing Sam H. Ham's book, Environmental Interpretation: A Practical Guide for People with Big Ideas and Small Budgets, Tracy suggested that interpretation should:

1. Be organized
2. Be relevant
3. Engage the audience on an emotional level
4. Be pleasurable

Interpreters utilize a variety of tools to accomplish these goals. Among the various tools are descriptive language, hand gestures, games, clever memory aids, and humor. Programs might also include storytelling, or use props to engage the senses of smell, sight, taste, touch, and hearing. Even with the use of these tools, a lesson might still fall flat if the interpreter does not include a secret ingredient -- enthusiasm. When an interpreter demonstrates enthusiasm for a subject, people notice and begin to care about the subject themselves. So go ahead, let your light shine!

Good interpreters also care about others. Making eye contact, pointing out safety hazards, and assuring that a group is comfortable and well hydrated are all ways to demonstrate caring and compassion towards an audience. An interpreter can further demonstrate these traits by situating themselves in a position where they will be visible to everyone, and by walking only as fast as the slowest member of the group. On the day that Tracy spoke about interpretation, she also led the class on a bird walk around the Rancho's grounds (Bird Walk with Tracy Drake). During that walk, someone spotted a gull flying overhead. I was walking next to Tracy and told her that I had given up identifying gulls. It was just too difficult. She put her hand on my shoulder and said, "That's ok," and then proceeded to simplify gull identification for me. (The trick is to look at first-year and adult gulls, ignoring the second-year individuals who often have quite different physical attributes. Additionally, by looking at the feet, a person can often identify a gull correctly.) Because of the way that Tracy responded to my comment, I felt valued. I didn't feel that I was an incompetent birder, or that I had said something stupid. Instead, my concern was acknowledged, and I was given an opportunity to improve my birding skills.

Naturalists might often feel as if they are expected to be experts in all areas of nature lore. While we certainly should strive to understand our subject matter, we should not be afraid to answer a question with, “I don’t know.” In fact, a naturalist may use that opportunity to engage his or her audience by turning the question around and asking the group to share their thoughts. Not knowing the answer to a question can also spur naturalists to look deeper into a subject and extend their own learning. Finally, in this world of constant connectivity an answer is never very far away. It is perfectly acceptable to pull out a phone and say, "Well, let's find out." The main point to remember is that, "I don't know," should be a starting point, rather than the end of the story.

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Part two of this series on interpretation will highlight examples from the California Naturalist classroom.


References:

Drake, Tracy (lecture on interpretation, at the Dominguez Rancho Adobe Museum, California Naturalist Program, Rancho Dominguez, CA, February 14, 2015).

Citizen Science Project: Collecting Spiders for the Natural History Museum of Los Angeles County

In March, students in the California Naturalist Program at the Dominguez Rancho Adobe Museum began collecting spiders as part of a citizen science project for the Natural History Museum of Los Angeles County. Led by Jan Kempf, students learned about the museum's ongoing Spider Survey and also received an introduction to spider collecting techniques.

Jan Kempf examines a False Widow Spider (Steatoda grossa)

The Spider Survey is the first comprehensive survey of spiders in the Los Angeles area. According to the Natural History Museum, most scientific collections only include spiders found in natural areas. This study is particularly important because its geographical range is a highly urban area. Located within that area are the major ports of Los Angeles and Long Beach. It is through these two ports that new species of wildlife, including spiders, often make their entry into the United States.

False Widow Spider (Steatoda grossa)

The survey began in 2002. To date, approximately 500 people have participated, and more than 6,280 spiders have been submitted to the museum. Originally, collection data was restricted to Los Angeles County. The popularity of the program eventually led the Natural History Museum to expand its survey area to five southern California counties. So far, the collection represents 33 families, 104 genera, and 75 species. Among them are several new records for the Los Angeles area including:

• Two species of jumping spider -- Plexippus paykulli and Mexigonus minutus

• Three species of orb weavers -- Larinioides sclopetaria, Metazgia zilliodes, and Metazgia wittfeldae

• Two species of cobweb weavers -- Latrodectus geometricus (the brown widow) and Steatoda nobilis

• Two species of Linyphiidae

 

Collecting Spiders

We often think of spiders in relation to the webs they spin. When collecting spiders, though, it is wise to think "outside of the web" and look all around. In addition to webs, consider where spiders may be hiding among plants, underneath bark and rocks, in leaf litter, and on man-made structures.

Hand Collection

This method is excellent for collecting the most visible spiders. Simply trap them, just as you might when you see one walking through your house. Instead of taking it outside, however, or flushing it down the toilet, send it to the museum!

Beating Method

Position a sheet underneath a branch or large leaf, then lightly hit the branch with a stick. You may be surprised to see what falls onto the sheet.

Sweeping Method

Use a butterfly net to sweep through grasses and low-lying plants. Be careful not to use the net around cactus or thorny plants as they will snag the net.

Looking Through Leaf Litter

Select an area that is moist, but not wet. Gather a pile of leaf litter and put it onto a white sheet. Use your hands to move the debris around and look for the movement of spiders.

An alternate method is to scoop leaf litter into a mesh bag such as produce might come in. Shake the bag over the sheet and see what falls out. Choose a bag with large, rather than small openings.

Pit Fall Trap

Pit fall traps are good for catching spiders as they hunt. To make a trap, take a small plastic tub and bury it so that the top is flush with the ground. Pour an inch of soapy water into the tub. One member of our class suggested that a lid can be suspended approximately one inch above the tub so that larger creatures, such as lizards, would not fall in. Be sure to check your trap every day.

Whichever method of collection you select, and you may want to try several, make sure to have containers ready. Our class used clear plastic vials, which can be purchased from biological supply stores such as local Rancho Dominguez company, BioQuip, but any small jar or tub will work.

Precautions

Whenever working with wildlife, whether big or small, it is important to take sensible precautions. Although spiders are predators by nature, we are not their prey, and the majority of spiders do not pose a threat to people. However, in the Los Angeles area we do have two types of spiders which can inflict a harmful bite. They are the black widow and the brown widow. Most people are probably familiar with black widow spiders. They have a shiny, black, rounded body and a red hourglass on the underside of the abdomen. Brown widows are thought to have come from South Africa and were established in southern California in 2000. They have a similar shape to that of the black widow, but the coloration is different. The brown widow's body is primarily brown, with geometric patterning on the abdomen. Additionally, the hourglass shape is more of an orange color. Brown widows also have distinctive egg sacs. When coming across an ivory colored, spiky egg sac, be aware that a brown widow is probably tucked into a nearby crevice.

Black Widow (Latrodectus hesperus)

Brown Widow (Latrodectus geometricus)

Brown Widow Egg Sacs

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

What To Do With the Spiders You Collect

In order for museum staff to make an identification at the species level, dissection is required. Perhaps it doesn't need to be said, but be aware that the spiders will have to be killed in order for scientists to study them. The usual methods of killing spiders employed by most of us (squishing, spraying, and flushing) won't yield a specimen appropriate for study. It is important to treat the spider in a way that will keep its body intact. One method of doing this is to add a cotton ball soaked with rubbing alcohol to the container. A second method is to put the spider in the freezer for 24 hours. Once you have done this, it is time to send your specimen(s) to the museum.

According to Jan, spiders arrive at the museum in all kinds of packaging. About the only way to fail is to enclose your spider in something soft, like a plastic bag, which may result in the spider arriving in pieces. Jan recommends putting the spider into something like an ordinary pill bottle and using a padded envelope for mailing. Make sure to include a data sheet from the Natural History Museum's website with your spider so that the museum will have accurate information on where the specimen(s) were collected. Send specimen(s) to:

Spider Survey
Natural History Museum of Los Angeles County
900 Exposition Boulevard
Los Angeles CA 90007

And that's it. Now go out and discover what's living in your own yard!

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Fun Facts about Spiders:

• Based on the submissions of the most enthusiastic survey participants, the average Los Angeles yard contains 150 spiders, representing 13 families and 21 species. 

• Worldwide there are 38,998 species of spider, distributed among 3,607 genera and 101 families.

• The most common types of native spider in the Los Angeles area are the black widow (Latrodectus hesperus), ground spider (Herpyllus propinquus), funnel weaver (Hololena curta), and orb weavers.

• The most common types of non-native spider in the Los Angeles area are the house spider (Parasteatoda tepidariorum), false widow (Steatoda grossa), cellar spider (Pholcus phalangioides), ground spider (Scotophaeus blackwalli), yellow sac spider (Cheiracanthium mildei), and Oecobius navus.

• Some spider eyes fluoresce at night.

• Reproductive features are only visible after the spider's final molt. Before then, it is impossible to determine gender.

• The only family of spiders that do not contain poison glands is the family Uloboridae.

• Female spiders are larger than male spiders of the same species. An exception is that wandering spiders are similar in size.

References:

Kempf, Jan, "Spider Survey" (lecture, California Naturalist Program, Rancho Dominguez, CA, March 21, 2015). 

"Spider Survey" Natural History Museum of Los Angeles County, accessed April 17, 2015, http://www.nhm.org/site/activities-programs/citizen-science/spider-survey

Vetter, Richard S. "Brown Widow Spider," Center for Invasive Species Research, University of California Riverside, http://www.nhm.org/site/activities-programs/citizen-science/spider-survey

I've Been Working at the Rancho

I was sick last week and had to miss class. Unfortunately, that absence put me over the maximum number of hours I was allowed to miss. I knew that I needed to make up those hours in order to complete the program. Thankfully, Alison Bruesehoff, Executive Director of the Dominguez Rancho Adobe Museum, had a suggestion. As part of the California Naturalist Program, each student is required to complete a Capstone Project, which benefits the program site. My Capstone Project is this blog, a chronicle of the California Naturalist Program at the Dominguez Rancho Adobe Museum, from a student's perspective. Several other students have been working on the design of a new children's garden. It was in this area that Alison thought I could do some extra work. The group will present their plan on the final day of classes. However, before the Rancho can begin implementing the new design, space needed to be cleared. The proposed area is currently used as an outdoor classroom in which elementary students learn to make butter, pan for gold, and create adobe bricks. As such, it wasn't really messy; it just needed a few people to come in and do some cleaning and brush removal. It is possible that some of my classmates had already spent time working on this area. I certainly don't want to claim credit for all the work. In fact, When I arrived yesterday, several men were working with chainsaws and clearing out the brush. My task was to move and organize the stacks of pots that had collected in the area and to transfer a scattering of hay into what will become a new compost area.

Before - part of the work involved moving and organizing a collection of pots

Adobe bricks drying in the sun

Although I had planned to spend much of my day at the Rancho, I had not anticipated that my younger son would wake up feeling sick and need to stay home. Although he was not feeling well enough to attend school, he was healthy enough to come to work with me. I was happy to spend some extra time with him and to have the opportunity to show off the Rancho. Since the end of January, I've spent a lot of time there, before yesterday, no one in my family had ever visited it.

I set to work while my son played, and it was not long before I came across my first wildlife discovery. A short, red centipede was hiding in one of the smallest terracotta pots. I carefully relocated the centipede to a patch of damp leaf litter. Excited by the find, my son and I kept a running count of centipedes. During the course of our work (yes, my son happily moved wheelbarrows full of wet hay to the new compost pile) we saw encountered centipedes.

Stone Centipede (Order Lithobiomorpha)

My next discovery was the empty shell of a terrestrial snail. It was not the type of snail that people often try to eradicate from gardens, which has a rounded, domed shell, but a different variety, flat, and approximately the size of a dime. It seems that both centipedes and this type of snail do well, living in moist, leafy environments.

Unidentified Terrestrial Snail Shell (Order Stylommatophora)

It was my son who discovered the sap. Children love sap. I remember picking it off trees when I was young. As a naturalist, I rather cringe at memories of driving nails into my front yard tree so that the sap would run, and I could play with it. This tree had several large sections of beautiful, glass-like sap. I am not an arborist. Therefore, I am not trained to recognize if an excess of sap indicates anything about the health of a tree. What I do know, is that it was visually stunning, and its sculptural nature almost compelled me and my son to explore it with our hands, as well as our eyes.

A sculpture in sap

It was while I was preparing to dump a load of hay that I saw a flash of red-orange fly out from the base of the compost pile. I tracked it with my eyes and made a mental note of where it landed. Then I did what I always do in that sort of situation -- rush for my camera. I was glad to discover that the moth had stayed in one place while I retrieved my camera and that it seemed willing to sit for a photograph. I have not yet identified the moth, although I suspect that it is in the family of Owlet moths, known as Noctuidae. If any reader knows the right ID, please be sure to add it to the comments!

Unidentified Moth (Family Noctuidae?)

Tiring of work, my son enjoyed spending the remainder of his time with the "roly-pollies," more correctly known as pillbugs.

My son, playing with pillbugs

He was especially happy to discover that one pillbug had golden tones.

Common Pillbug (Armadillidium vulgare)

Other wildlife sightings included a mourning dove...

Mourning Dove (Zenaida macroura)

a gray bird grasshopper...

Gray Bird Grasshopper (Schistocerca nitens)

... and an abandoned beehive, which had probably been covered to prevent future colonies from taking up residency because the tree sits just to the side of a heavily trafficked walkway.

Screened-off opening in California Pepper Tree

Detail of honeycomb structure

Finally, I spotted a black-throated gray warbler -- a new addition to my life list! The bird was too high up in the tree for me to distinguish much detail at the time. All I knew was that it looked and behaved differently than anything I had seen to date. My best guess when reviewing the photographs at home was that it might be a juvenile black-and-white warbler. Although the website eBird suggested that the location and timing might not be correct for that identification, it seemed the best match. I entered my photographs into iNaturalist and asked for help with confirming my ID. Almost immediately, I received several responses from iNaturalist community members. They all agreed on one identification -- black-throated gray warbler. I then went back to eBird and looked more closely at historical data for the black-and-white warbler. There have been April sightings of the black-and-white warbler in the South Bay area in previous years. Furthermore, my field guide suggests that this area does fall within the extent of the bird's irregular range. For now, though, I am recognizing the community ID on iNaturalist and calling it a black-throated gray warbler. What's your opinion? Enter it in the comments section!

Black-throated Gray Warbler (Setophaga nigrescens)

Black-throated Gray Warbler (Setophaga nigrescens)

Black-throated Gray Warbler (Setophaga nigrescens)

With all my bird watching and bug spotting, you might wonder, did I actually complete the task I was assigned? Yes. When my son and I left for the day, the area was cleared and ready for the next phase of development. I can't wait to see how the new children's garden progresses.

After - pots are cleared and the compost pile has grown

To see more photographs from the Dominguez Rancho Adobe Museum and the South Bay area of Los Angeles, click on the following links:

• Dominguez Rancho California Naturalist Project on iNaturalist 

• Neighborhood Naturalist on Flickr

Geology Part Two: Natural Disasters

by Amy Jaecker-Jones


As a child, we practiced "duck and cover" drills in school. At home, the slightest bit of shaking would send me running to the nearest doorway. The very possibility of, "THE BIG ONE" happening in my lifetime, had 8-year-old Amy making plans for a move to Florida.

Natural disasters are a fact of life, not just in California, but everywhere. They include powerful forces of nature, cause serious devastation, and remain in our memory and imagination long after the actual events have taken place. Mount Vesuvius erupted in 79 A.D., and we're still talking about it. Such is the mythic appeal of that event that an exhibition of artifacts tours the world. Recent events, such as Hurricane Katrina and the series of Japanese earthquakes, which caused both a tsunami, and the Fukushima Nuclear Power Plant disaster have had a profound influence on our collective conscience. They've renewed conversations about racism, social justice, urban planning, and the safety of nuclear power plants.

Professor Joe Holliday, of El Camino College's Earth Science Department, makes a special study of natural disasters, and he shared his knowledge with students in the California Naturalist Program at the Dominguez Rancho Adobe Museum.

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When we discuss earthquakes, the term, "fault," usually enters the conversation. A fault is a crack in the earth's crust. It may align with a transform plate boundary as in the case of the San Andreas Fault, but in most cases, a fault is not along a plate boundary. (For a discussion of plate boundaries see the previous post - Geology Part One.) A fault can be very small or so large that it is visible from space. The area of land between faults is much less than that covered by plates. Fault areas only span 20-30 miles. An earthquake occurs when there is a sudden movement along the fault. This movement is described in three ways: extension (normal), compression (thrust, reverse), and transform (strike-slip).

An extension fault is where two sections of crust pull apart, forming a valley in the gap. The Basin and Range province of California includes an example of an extension fault. The Transverse Ranges of southern California are examples of compression fault activity, in which one block of crust slides on top of another, often forming mountains. In contrast, transform faults, such as the San Andreas, do not show much vertical movement. Instead, opposing blocks of crust slide past each other. In California, Professor Holliday said, compression faults generally occur north of Interstate 10; extension faults occur to the south.

Earthquakes reveal weaknesses in our infrastructure. The 1933 Long Beach earthquake set new standards for building. Earthquakes in Whittier and Northridge both occurred along previously unknown compression faults. A friend of mine describes house sitting during the Northridge earthquake. She had to call the homeowners and tell them to return because, "their pool was in the living room." I remember driving up to Sacramento that same year and taking a picture of a collapsed portion of the 5 freeway. Professor Holliday's faculty page at El Camino College shows many examples of buildings damaged in these two earthquakes.

Damage to the 5 freeway following the 1994 Northridge earthquake.

What are the dangers?

 

In addition to lives lost, "THE BIG ONE," when it comes, will cost hundreds of billions of dollars in damage to housing, commercial buildings, and infrastructure. The last time in recorded history that the San Andreas Fault moved in a major way was in 1680. We are overdue for another major earthquake.

Liquefaction is a risk in flood plains and harbor areas where the ground is saturated due to a high water table. When liquefaction occurs, the ground experiences a decrease in strength and stability, causing buildings and other structures to lose their foundational support. The depth of a basin correlates to the amount of shaking experienced in that region. The Los Angeles area's sediment is five miles deep. Therefore, areas at risk of liquefaction will also experience five times more shaking, for five times longer than other areas. Because liquefaction zones commonly occur along the coast, where our nation's most important shipping ports are located, earthquakes may cause a significant economic impact that goes beyond the cost of damages and repair.

Landslides may occur in areas where sedimentary rock is steep. Slides may occur quickly or slowly. A slump landslide is one which happens slowly and has the potential to move houses and shut off traffic.

What should we do?

 

Proponents of an early seismic warning system are on the right track. Construction of such a system is an expensive option, but one that is truly vital to the health and safety of California's residents. Fortunately, in 2014, Congress approved $5 million for this purpose. According to the Los Angeles Times, the system may be available to some schools, fire stations, and private businesses later this year. Eventually, scientists hope, the general public will receive notice of an impending earthquake seconds before shaking begins. Notices would arrive via cell phones, computers, and specialized weather radios. Mere seconds may not sound like much time, but it might mean the difference between life and death. An early warning system would allow people to find safe places to shelter, fire stations to open their doors before power outages occur, construction firms to stop heavy equipment, and for rail systems to stop or slow trains.

Save your precious belongings!

Prepare! Prepare! Prepare! That's good advice in any context, but especially in relation to earthquakes. Professor Holliday says that he makes a habit of walking through friends' houses, demonstrating how many loose objects would fall or fly in the event of an earthquake. I admit, I've been looking at my own house, and assessing how unsafe it might be. Much of our heavy furniture and picture frames are bolted to the wall, but not all of them. Additionally, I have too many small items sitting on shelves and tables that I could secure by using an adhesive such as museum putty, wax, or gel. Like many other parents, when our baby years were past, my husband and I removed the cupboard and drawer locks in our kitchen. I've been thinking about putting them back to prevent all of our dishes and pantry items from ending up on the floor. An even simpler approach, is to follow my grandmother's example of wrapping rubber bands around cupboard door knobs to prevent their flying open.

My grandmother's simple safety measure.

One major improvement that homeowners can make is to bolt their houses to the foundation. For many modern homes, this might already be done. I live in an old house which is not bolted to the foundation. Years ago my husband and I researched having a company provide this service, and for reasons I cannot remember, opted not to have it done. Perhaps we were worried about cost. Although this sounds like an expensive fix, according to Professor Holliday, it can be done by homeowners themselves without spending a lot of money.

Professor Holliday advises putting together a household survival kit. Pack food, water, medicine, and first aid supplies. Also include fix-it directions for common household problems. Do this BEFORE an emergency happens. Electric, gas, phone, and internet connections may not be available in the days immediately following an earthquake. Additionally, grocery stores will most likely be closed, partially for the reasons described above, but also for clean up. Professor Holliday said that following the Whittier earthquake, many items fell off grocery store shelves including food, alcohol, and household chemicals. These items combined to form a toxic mess.

We are a car culture. Many of us commute more than an hour to work every day. What happens, Professor Holliday asked, when an emergency occurs that threatens to strand us at work? If the roads themselves haven't been damaged, they are certain to be jammed, and you may find yourself walking home. He recommends keeping a pack with you, which contains walking shoes and water. If you wish to add to your pack, there are plenty of websites which will help you to select useful items.

In addition to earthquakes, what other types of disaster might we face in California?

 

Perhaps you've heard of the "100 Year Flood?" It's gained some press attention in recent years. According to Professor Holliday, a major flood will have the same death toll as a major earthquake but occur over a longer time period. Personal property damage from flooding will also be greater in the event of a flood as memorabilia, important documents, carpets, and walls are all damaged or destroyed by high levels of water.

We don't usually think of our state as receiving enough rain to cause major flooding, especially not in these days of drought, but the danger exists. Concentrated moisture flows through the atmosphere in "rivers." Atmospheric rivers can cause continuous rainfall for up to a month. One of these storm systems arrives in California approximately every 100 years. They can occur in northern or southern California. The last time the state experienced such large-scale flooding was in Los Angeles and Anaheim in 1938. Currently, we do not have the capacity to handle a major long-term flood situation. Existing reservoirs would fill quickly, and the ground become too saturated for water to percolate into underground aquifers.

Fortunately, urban planners seem to be aware of the potential risks of flooding and are incorporating their ideas into disaster plans. Most people, however, are not prepared for flooding, especially for one of such magnitude. Many of the same precautions recommended for earthquakes can be applied to flood preparation. In addition, it is wise to invest in water-safe containers for important items and to store your most beloved belongings in the upper sections of a room or house.

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As you might have guessed (because I am part of the California Naturalist Program), I did not follow 8-year-old Amy's advice to move to Florida. I'm still waiting for "THE BIG ONE." Hopefully I (and you) will be prepared when it comes.



References:

Holliday, Joe, "Soils, Geology and Weather" (lecture, California Naturalist Program, Rancho Dominguez, CA, January 31, 2015).

Lin, Rong-Gong II. 2014. "California Receives U.S. Funding for Earthquake Early-warning System." Los Angeles Times, December 14. http://www.latimes.com/local/california/la-me-quake-early-warning-20141215-story.htmlhttp://www.latimes.com/local/california/la-me-quake-early-warning-20141215-story.html

Oskin, Becky. 2014. "Fault Lines: Facts About Cracks in the Earth." Livescience.com, September 25. http://www.livescience.com/37052-types-of-faults.htmlhttp://www.livescience.com/37052-types-of-faults.html

Geology Part One: Digging Beneath the Surface of California

by Amy Jaecker-Jones


One of the pleasures of being in the California Naturalist Program is hearing from its faculty of diverse and highly educated instructors. Geology Professor Joe Holliday is no exception. Professor Holliday teaches in the Earth Science Department at El Camino College and travels as a naturalist for the National Geographic Society. During his lecture, he discussed the movement of the earth's plates and how that movement relates to the type of soil and topography found in California. He also spent time exploring one of his favorite subjects - natural disasters.

Part one of this series on geology will deal with what happens beneath the surface of California.

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The earth consists of a solid inner core, a molten outer core, a ductile mantle, and a comparatively thin crust. Some readers may remember making Play-Doh models with separate colors to designate the core, mantle, and crust.

Actually, Play-Doh is a wonderful metaphor for the inner-workings of the earth, and one that Professor Holliday particularly likes to describe the mantle. Like me, you may have thought about the mantle, and imagined it to be a liquid layer of red-hot lava. It is not a liquid, however, but a solid that moves.

Take a moment to remember the feel of Play-Doh in your hands. It's solid. It can take a definite form. If you turn your hand sideways, it won't drip. But it's not like other solid materials which must remain in one shape. You can squish it. You can squeeze it. You can re-form it again and again. It is this ductile quality of the mantle and the movement of tectonic plates above it that allows the surface of the earth to be constantly re-forming.

On top of the mantle lies the earth's crust. The crust is made up of different plates that move under, over, and against each other. There are three types of plate boundaries, and California is distinguished by having all three active within its borders. For this reason, it is worth learning a little about each type of boundary.

• Divergent plate boundaries primarily occur in the ocean. As the mantle moves, lava begins to rise. It seeps through cracks in the crust and spreads the two plates apart, creating new land in the process. This continuous process of spreading could continue without ceasing if it were not for the next two types of plate interactions.

• Convergent plate boundaries may be oceanic or continental. In the case of an oceanic plate colliding with a continental plate, the thinner, heavier oceanic plate bends under the continental one. The result is a rise in the continental plate. The oceanic plate, now forced underneath the continental plate, begins to melt. As it melts, some of the magma rises again and exits the crust through a volcano. In the case of two continental plates coming together, there is not enough difference in their weight for one plate to bend under the other. As a result, they smash together. Hot rocks become welded to each other. Some magma rises and cools to become mountains. The rest of the magma is pushed downward into the earth.

• Of the three types of boundaries, transform plate boundaries are the most important in California. This type of boundary is the primary cause of earthquakes. The San Andreas Fault is our most famous example of a transform plate boundary. Transform plate movement is also responsible for creating California's Central Valley, a sunken area, surrounded by tall mountain ranges. Unlike other plate boundaries, transform boundaries do not involve magma. Two continental plates move past each other, but instead of sliding smoothly, they grind against each other and get stuck. Then with a jerk, they move some more. Every 200 years, approximately, the movement is jerky enough to cause a major earthquake. To a person standing near the epicenter of one such extreme quake, the sound would be similar to that of an airplane crash.

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I learned one fact in this lesson that threatened to change the way I see myself as a Californian. Perhaps, for you, it will only be an interesting bit of trivia, but for me, it was shocking. In geologic terms, according to The California Naturalist Handbook, much of California is not a part of North America. Everything to the west of the San Andreas Fault sits on the Pacific Plate. As the name implies, the Pacific Plate is mostly covered by ocean. In fact, the only part of the earth's crust that sits on the Pacific Plate is in western California. All the land to the east of the San Andreas Fault, including the entire rest of the country is on the North American Plate (de Nevers, Edelman, and Merenlender 2013, p.32-33). Suddenly, reading that fact, I didn't know who I was anymore. I thought I knew my place in this world. I live in: Los Angeles County, southern California, in the western United States, on the continent of North America. As for my geography and nationality, this understanding is still true. But geologically, I live somewhere else. My house sits on the Pacific Plate.

However, despite years of jokes, California is not physically apart from the rest of the country. If I drove out to the San Andreas Fault, I might see a jagged line of demarcation, but I would not see a bottomless gap dividing the Pacific and North American Plates. The landmass that I live on is indeed part of North America. The separation between plates occurs 10 miles beneath the surface. The next part of this series will discuss what happens when the San Andreas Fault begins to move as well as other potential natural disasters.


References:

de Nevers, Greg, Deborah Stanger Edelman, and Adina Merenlender. 2013. The California Naturalist Handbook. Berkeley: University of California Press.

Holliday, Joe, "Soils, Geology and Weather" (lecture, California Naturalist Program, Rancho Dominguez, CA, January 31, 2015).

 

Trail Walk with Loretta Rose, Manager and Naturalist at the George F Canyon Preserve & Nature Center

by Amy Jaecker-Jones

On this warm and sunny day in February, students in the California Naturalist Program were led on a walk by Loretta Rose, Manager and Naturalist at the George F Canyon Preserve & Nature Center. Located in the city of Rolling Hills Estates, George F Canyon is operated by the Palos Verdes Peninsula Land Conservancy. A stream, partly fed by underground springs, flows through the property seasonally. Spur trails connect the canyon to 96 additional miles of walking trails on the Palos Verdes Peninsula.

Before it became part of the mainland, the Palos Verdes Peninsula was one of the Channel Islands. As such, it shares much of its ecology with nearby Catalina Island. Because of its shape, which is something like the back of a turtle, one can easily imagine it surrounded by water. The bedrock in this area is Catalina schist, a hard, metamorphic rock that appears blue-gray, green, or purple when wet. Although Catalina schist lies under the entire Los Angeles basin, it is only exposed at the surface in two locations - Catalina Island and George F Canyon. The relative rarity of visible Catalina schist makes George F Canyon an important natural history site and a must-see for geology lovers.

Catalina Schist

As we walked, Loretta described some of the challenges of land management. When the city of Rolling Hills Estates turned over operation of the canyon to the Palos Verdes Peninsula Land Conservancy, the area was landscaped more like a park. Under the Conservancy's leadership, native plant communities were restored. Despite the renewed presence of native plants, certain non-native varieties such as castor oil plant, eucalyptus, Brazilian pepper, Italian milk thistle, and Algerian ivy still survive.

Castor Oil Plant (Ricinus communis)

Recently 65 California fan palms were removed; all of them were over 50 feet tall. Although native to California, the fan palm was not historically found on the Palos Verdes Peninsula. It arrived at George F Canyon via bird and has proved to grow quite successfully. At this time, the canyon is not yet free of California fan palms. The question of whether or not more California palm trees should be removed proves just how nuanced the issue of native versus non-native plants can be. As Loretta told the class, "If you see something that looks really different from the environment around you, it probably is." California fan palms do tend to stick out visually, and they compete with native trees and shrubs for water. However, they also provide good nesting sites for orioles. And, as one member of the class suggested, "If birds [rather than humans] are bringing the seeds in, haven't they become natural?" As long as birds continue to bring seeds to George F Canyon the presence of the California fan palm will probably continue, as will the effort to curb its growth.

Arroyo Willow (Salix lasiolepis)

Loretta preferred to remain positive, however. She pointed out examples of mature Arroyo willow trees lining the stream. Tufts of white floated through the air around us and bees hummed busily at the trees' yellow flowers. Not much farther down the trail, the buzzing increased, signalling the presence of a wild hive off to the side. Following recent rains, native plant life was lush and abundant. Loretta held up a trailing vine, which is found quite commonly in California. The wild cucumber, also known as, "marah," or "man-root," is California's only non-woody native vine. Small white flowers in early spring, soon give way to large, green, spiky fruit. Other flowering native plants included Arroyo lupine, California poppies, Canyon sweet pea, bladderpod, lemonadeberry, and California bush sunflower.

Loretta Rose Shows Wild Cucumber (Marah macrocarpa)

In addition to its geology and plant life, George F Canyon, also has an interesting history. The 36-acre parcel, once owned by the Stein and Hale families, was given to the city of Rolling Hills Estates in 1982. When donating, the two families asked that the canyon be named something other than Stein or Hale (although the current nature trail bears both names). The city then began the work of selecting an appropriate name. According to Loretta, different names were being considered before an elderly gentleman walked into a meeting carrying an old map. Written on the map, above the canyon's location was, "George F Canyon." As written, there was no period following the "F" and no indication of what the initial stood for, or who George F might be. The committee felt the name was appropriate, however, and designated the new park as George F Canyon. Over the years, many have tried to unveil the identity of the mysterious George. An article from the Los Angeles Times in May of 1996, presented several theories, among them that he might, in fact, have been George H. Bixby. Known well to residents of the South Bay, George H. Bixby was a prominent landowner in the early 1900s. There is no indication that Mr. Bixby is the George mentioned on the old map, and the Times also suggests San Pedro butcher George Vickery and Wilmington contractor George Oden as possibilities. We may never know the answer to the question of George F's identity, but can still enjoy the canyon that bears his name.



More images from the field trip to George F Canyon may be found on Flickr at the following link:

George F Canyon Photos 

Visit George F Canyon in person, or by going to the following link:

Visit George F Canyon Preserve & Nature Center

27305 Palos Verdes Drive East, Rolling Hills Estates CA 90274

(310) 547-0862

the Nature Center is open Friday 1pm - 4pm

 Saturday and Sunday 10am - 4pm

other days by appointment

References:

Johnson, Tracy. 1996. "Curious George: Nature Center Takes Title from Canyon's Enigmatic Namesake." Los Angeles Times, May 31. http://articles.latimes.com/1996-05-31/local/me-10457_1_nature-centerhttp://articles.latimes.com/1996-05-31/local/me-10457_1_nature-center

Rose, Loretta (nature walk, George F Canyon, Rolling Hills Estates, CA, February 21, 2015)