Guest Speaker: Adrian Cotter
7:30pm, Wednesday, May 27th, 2015
FREE at Green Apple Books on the Park, 1231 9th Ave, San Francisco, CA
Guest Speaker: Adrian Cotter
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Joel Pomerantz (my partner in this lecture business) talked to us on March 19th, 2015 about his research into the flood of 1862. At first he did not find a whole lot, until he stumbled across the term “freshet”. That opened up a whole new line of research — which led to this wonderful and somewhat unconventional lecture — a “choose your own lecture” adventure: offering a list of topics on which he could speak.
He did give some background to start. The term “atmospheric river” is a relatively new one. I hadn’t heard of it myself until I heard a lecture on drought last fall, but it popped up in the news a lot at the start of our winter storm cycle (the threat of which caused more chaos than the actual event this year). These rivers in the sky are actually the delivery mechanism for a lot of moisture from the the equator to landmasses. The moisture isn’t necessarily even visible from space only recently have microwave satellites been able to track them.
One of these rivers pushes up toward the northwest, and under certain circumstances, storms in Alaska (the results of other atmospheric rivers) push these rivers further south into California. The total water in these systems can be huge (10 to 20 Mississippi’s worth), and what fell in California in 1862 was exacerbated by a drought in the prior year, and a hard freeze that followed. What measurements we had: San Francisco saw 24”-37” of rain in January alone (19-20 is the average for the year). In gold country there was 108” in a month.
All this wrought terrible destruction, pretty much every mill, ferry, and bridge were washed out (many many deaths happened with people trying to cross rivers), tens of thousands of dead cattle washed up on beaches, low lying farms inundated, Sacramento flooded.
Newspaper accounts of the time (akin to the blogs of today) had all sorts of accounts of how terrible it was. Every day people thought it could not get worse, and each day it did. A Southern Californian woman recounted how in a 6 week stretch there was not time to dry even a handkerchief.
Given the prior year’s drought, sediment got picked up from the ground rather than the water being absorbed — and given also the blasting going on for mining, a tremendous amount of soil and rock was moved and polished by the high fast moving water. Water covered 30’ high telegraph poles in some places and steamships were able to go anywhere.
The freeze that followed didn’t stop it. The freeze was a deep one down to sea level, but it didn’t stop the water from moving and ice tsunamis formed — ice piling upon ice, pushing up onto land crushing whatever might be in its path.
San Francisco Bay clocked no flood tides for over a week, raised as it was by 7’, and the water was fresh enough that steam ships didn’t have to trek to their usual freshwater streams to get water.
The effects did not happen all in one go either. Drought followed in 1863 and 600k more cattle died, pretty much the last of the stock that came from the original Spanish settlements. Michael Barber of UC Davis thinks that this is when native grasslands were supplanted, when new cattle was brought in directly from the east. Tree squirrels may have also taken their place at this time — so many ground squirrels were killed into the floods.
The greatest source of information about the floods comes from Sacramento. Governor Leland Stanford was inaugurated on Jan 10th, 1862 and was said to have had to row to the ceremony. Business had to be carried out on the 2nd floor of Sacramento, and 1000s of miners came down from the hills looking for a way back to San Francisco. A fair number of people turned their backs on California altogether.
The story quickly made its way into stories and song: Bret Harte’s Luck of Roaring Camp (the story was very successful, the author himself helped rescue people during the floods), a musician Max Zorer who named his songs after the flood (The California Flood Mazurka Dance), and a minstrel song published in 1863 called Down By the River Lived a Maiden, by H. S. Thompson, about a woman who drowns while chasing her ducks away from the river, which later was the inspiration for a song you are all familiar with Oh My Darlin’ Clementine. Joel gave a fabulous rendition of the original — an “old timey” sounding tune, with its amusing but ultimately sad lyrics (sadly my recording of this event failed entirely).
Joel had us speculate on why this disaster faded into the background, beyond the terminology, until recently there was little to be found on the subject. There is some level of time passing — we would not expect much of a history of Hurricane Sandy in 150 years perhaps, except that we are now building on the places that were designed as flood plains in the 1850s. His hypothesis is that it might be the flood control administrators who did not want to talk about it — the storm was of such a magnitude that it is unlikely we could build to it. It’s only recently that people have begun to think about a response (on such effort referred to as the Ark Storm). 16 million people live in areas which were underwater in 1862.
How long ‘til the next one? It is really impossible to say. There have been 2-5 storms of this magnitude in the last 2000 years (measuring from sediment layers taken from lakes). Ultimately, it is up to us citizens to remember, research, pass on, and act on this kind of knowledge.
At the end of the lecture, I am sure that Joel could have gone on much longer. Keep an eye on http://thinkwalks.org for updates and future talks on his flood research.
Note: This is out first of many talks outside of the Randall (the Randall is undergoing reconstruction through until the Fall of 2016). Make sure to note the date, time, and location. We won’t likely to be on the third Thursday too often.
The Art and Exploration of Creating a Bird Book
Guest Speaker: Keith Hansen
7:30pm, Wednesday, Apr 29th, 2015
FREE at Green Apple Books on the Park, 1231 9th Ave, San Francisco, CA
Keith Hansen is a wildlife artist who specializes in the inspirational and accurate portrayal of birds.
His most resent endeavor has been a 14 year project illustrating the book “Birds of the Sierra Nevada: Their Natural History, Status and Distribution”, authored by Ted Beedy and Ed Pandolfino. He illustrated about 1,400 portraits of the 320 species that occur annually somewhere, anywhere, and everywhere in the Sierra. He will be talking about the production of his illustrations and the birds themselves.
If you can’t make this talk — his workspace, The Wildlife Gallery” is located in Bolinas California where people can view originals, prints, and the various works that are on display (and the birds visible outside his window!).
More about Keith and his work can be found at keithhansen.com.
Darwin, whilst voyaging in Patagonia, was one of the first to observe the impact of invasives, but it wasn’t until 1958 with Charles Elton’s the publication of “Ecology of Invasions by Animals and Plants” before much thought was given it. And only in the 80’s — during a conference on mediterranean climates, where speaker after speaker talked about invasives — that the study of invasions became a field of study.
Nowadays it occupies the attention, resources, and budgets of many organizations, where invasive organisms threaten to displace natives. Lew Stringer (on January 15th, 2015) talked to us about what is involved in trying to make the Presidio and other places free of 3 weeds in particular: iceplant, mattress weed, and english ivy.
Ice plant, Carpobrotus edulis, known in it’s native South Africa as sour fig, or hottentote-fig (it’s fruit is edible) has been in California for 150 years. It arrived in California with the intercontinental railroad, where the rail builders were using it to stabilize railroad levees, and in the 40s and 50s, CalTrans decided to use it for the highways now crisscrossing the state. People thought it was pretty, and soon it was being planted everywhere, and now can be found in pretty much every Mediterranean region.
For years now, up & down coast, people have been working on removing it. The Presidio has little left, mostly removed by hand over the years. It’s a labor intensive project, but easy to keep out. Point Reyes, has done it through various methods, but is soon to embark on a 3 year project using herbicides.
Mattress Wire Weed, Muehlenbeckia complexa, or mattress vine (and a host of other vines) is from New Zealand where it grows in little clumps on dunes. Here, much like Kudzu, it blankets trees and shrubs, and vaults up trees and smothers them. It was first observed in 1971 on the North Coast. No one is sure how it came, but likely through gardening — it makes for great shrubs and topiaries.
In the Presidio, it ended up blanketing a couple creeks (one which was only rediscovered in the 90s): Lobos and Dragonfly. Under the Mattress Wire Weed at Lobos Creek, they found tunnels under the canopy it was so dense. Both of the creeks have been largely restored to native habitats, but you can still find big piles of the weed at Sutro Baths.
English Ivy is the big fight that remains in the Presidio — with an attempt to remove it in the historic forest, and replace it with other understory. The ivy was brought over from the Canary Islands in 1875 by a horticulturalist who was very excited by ivys. But it what we refer to as English Ivy is likely a swarm of species and it is likely a hybrid species. Hybrids are some times especially successful and the term hybrid vigor refers to this. It has become a problem in the Sierras, in redwood forests, and grows in a abundance under the eucalyptus on Mt Sutro.
It is particularly hard to remove. It only produces seed when it leaves the ground. Weeders will cut the ivy at the base of the tree, so it is no longer reproductive. From there it is hard work. Although having a herd of goats can help — it takes vigilance to keep it from coming back.
All this work to keep back invasives is both time and budget intensive. And it is becoming more controversial — especially where the removal of trees comes into play — and some people beginning to question whether it is worth it, looking at the novel ecosystems that form. Hawaii has seen a huge loss of species to invasives, but its overall diversity has not changed much. Not that that is always the case, take Sutro forest, for instance, which has low biodiversity because of the dominance of eucalyptus and english ivy.
It is clear that invasions will keep happening, including more insidious ones like sudden oak death and other plant pathogens, some organizations are working on early detection networks and rapid response before things get out of control. We can look forward to continued discussion around the value of native plants, planted forests, and resistance to unwelcome plants. In the meantime, we can enjoy some of the wonderful landscapes in the Presidio that Lew has helped uncover.
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Joe Jordan led us on a glorious tangent filled romp through the sky — chasing rainbows and other phenomena with photos, chalkboard drawings, and props.
Joe, former physicist NASA, current director of the Sky Power Institute (http://www.sky-power.org) talked to us at the Randall on November 20th, 2014 about all manner of sky phenomena and the physics behind them: the complexities of rainbows, sun dogs, sun pillars, moonbows, haloes, glories, contrails, green flashes, castles in the air, the directionality of meteor showers, and more!
A lot of what we see looking up, or what we see downwards looking out of a plane is the result of ice crystals in the air, their orientation to the sun, and the observers particular perspective.
Sun pillars for instance — where a column appears to rise from the setting sun — is sunlight reflecting off the undersides of ice crystals. It is the same effect as the sun reflecting off the waves toward you, just in the sky. Other effects depend on the angle that light is hitting the crystal, and where that crystal is in relation to the light and you.
A more complicated phenomena, but one of my favorites, are glories. Sitting on the shadow side of the aircraft — as you are coming into land and passing over clouds, you might see a glory in the clouds, a circular rainbow. At the center of that you might be able to make out the shadow of the aircraft.
(If you are a SCIAM subscriber you can read more at http://www.scientificamerican.com/article/the-science-of-the-glory/)
Joe talked a fair amount about the appearance of sun rays fanning out. Sun beams are essentially parallel given the distance the travel from the sun. The fanning out is an optical illusion akin to how train tracks look when we look down them.
We spent the longest time with the intricacies of rainbows, the bending of light through raindrops and how that gets to our eyes. Multiple bounces leads to double and triple and more rainbows (in the lab, this has been done up to the 15th order, but in nature you’d be lucky to see a 5th order rainbow).
My favorite factoid of the night is that although what we see a rainbow as a static thing up in the sky, what that rainbow actually is is an animated mosaic projected onto our eyes — millions of rain drops bending light in our direction, changing colors until they fall “out of the picture.” followed and replaced by the raindrops above.
The Most Extreme Storms Yet
Guest Speaker: Joel Pomerantz
7:30pm, Thursday, Mar 19th, 2015
FREE at the Randall Museum, 199 Museum Way, San Francisco, CA
Joel will share his research on the weather disaster that determined so much of what’s around you today. In early 1862 the sky dumped upwards of ten feet of rain in the mountains (about four feet in San Francisco). In the middle of that, there was a hard freeze for a week down to sea level. Thousands died. No previous research has done so much to connect the dots. Come learn about the widespread disaster that spanned more than four states (before all were states), changed the course of rivers, destroyed the California economy and brought in invasive grasses, among other stunning details.