Posted by: walkingthefault | March 5, 2008

Why is Berkeley Moving?

My last post, in which I mentioned the subject of the Pacific Plate twisting slowly to the north-west, while the North American Plate slides in the other direction, generated the question “What makes the plates move anyway?” Not only is Berkeley slowly moving along as part of the edge of the Pacific Plate, but two areas of Berkeley are moving at different speeds. And it has nothing to do with politics.

La Loma Steps Exit

Would you believe it if I told you that the part of Berkeley at the top of these beautiful La Loma Steps is moving in a different direction relative to the part where the cameraman is standing? Right now, you can see that there is absolutely no evidence of that fact. But there will be very soon, and when that happens, it will be frightening.

All of the tectonic plates which make up the surface of the earth, including the ocean floors, are moving around relative to each other like slabs of congealed scum on a slowly simmering pot of soup. Berkeley is merely a couple of insignificant pieces of congealed scum sliding around right on the edge of the Pacific Plate.

Calling Berkeley a couple of insignificant pieces of congealed scum sounds like it came right out of the mouth of extreme right wing talking head Bill O’Reilly from the Fox Television Network News, but in fact that’s a good analogy. For many years, scientists have used the picture of a pot of simmering soup to illustrate the movement of the earth’s tectonic plates.

In some cases, two pieces of scum slowly crash into one another and pile the earth’s crust high up into the air, like the Himalayas, in what is known as a convergent boundary; in some cases they split apart leaving a void, as is the case underneath the center of the Atlantic Ocean, giving rise to islands like Iceland and the Azores, in what is known as a divergent boundary; and in some cases two pieces slide slowly past one another in what is called a transform boundary, resulting in a fault system like what we have here in the Bay Area.

Atomic and residual energy from the center of the earth is the source for the heat for the simmering soup with its convection currents that cause the earth’s crustal plates to move relative to one another, and the Berkeley flatlands to slide north-west a little bit faster than the Berkeley Hills. See, it’s not politics at all!

Where the Pacific Plate and the North American plate meet is at the complex series of faults known as the San Andreas Fault, the Hayward/Rodgers Creek Fault, the Calaveras Fault, and other minor faults, some yet to be discovered. It’s a mess, it really is. It wouldn’t matter if it were just a bowl of soup covered in cracking pieces of scum, but it’s the place where we live!

The story gets worse. If Berkeley were, in fact, moving slowly, we might not get devastating earthquakes every hundred or so years, but unfortunately it’s all jammed up. The two pieces of real estate on the edge of the Pacific Plate are stuck fast against each other at a line a little way up the Berkeley Hills. The piece of crust between the Hayward Fault in Berkeley and the San Andreas Fault is struggling to move north-west, but cannot right now because it is jammed, and the piece of crust between the Hayward Fault in Berkeley and the Calaveras Fault in Concord is struggling in the same way, but at a slower speed, because it is stuck where the Calaveras Fault meets the North American Plate.

Let’s take a look again at the Bay Area fault diagram (courtesy of USGS).

Bay Area Faults

Now think once more about the scum on the soup analogy, and you may understand why two pieces of Berkeley are moving, or would be, if they weren’t stuck together while the simmering soup underneath inexorably increases the pressure. One day soon, it’s got to break.  

Posted by: walkingthefault | March 3, 2008

Some Clarifications & Additional Information

A few people have given me some feedback and comments on my recent posts, which I have paraphrased and then addressed, as follows:

You talk about the possibility of the Hayward Fault through Berkeley “ripping open like a burst zipper”. Is that where the epicenter will be?

The short answer is, not necessarily. In a big earthquake there are three potential problem areas where the most damage can occur, and they may not all be in the same place.

  1. At or around the epicenter, which is the point on the earth’s surface above the hypocenter where the earthquake originates.
  2. Where the fault actually rips open (the zipper effect).
  3. Wherever there is extreme vulnerability due to ground conditions and/or poor construction.

So, where do you want to be when the earthquake happens? Preferably as far away as possible from all of the above.

In the 1989 Loma Prieta Earthquake, the epicenter occurred in the Santa Cruz Mountains, far from inhabited areas. That’s near where the fault ripped open too. But the greatest damage occurred in San Francisco’s Marina District, 60 miles away, due to the liquefaction of the soil and construction deficiencies, and on Oakland’s Cypress Structure, 65 miles away, due to inadequate freeway construction.

In the Great 1906 San Francisco Earthquake, the epicenter occurred two miles offshore near Mussell Rock. Where the fault ripped open though was near Olema, forty miles to the north, “where the fault zone is half a mile wide, and filled with soft soils, crumbling limestones, rotting granites, and generally pulverized rocks” (Simon Winchester). But as we well know, the greatest damage occurred in San Francisco itself, due mainly to the ensuing fires and lack of water

In your Scary Picture chapter you show that the fault line passes right under the Tots’ Playground in Codornices Park. How do you know it will be exactly at that spot? Couldn’t it be a hundred feet to the east or west?

Yes, absolutely it could. But really, what difference does it make? The Hayward Fault is actually a “complex zone of deformation which can span hundreds of feet in width”, the leftover evidence of many earthquakes over thousands of years. Various university teams, together with the USGS have dug trenches at various places across the fault in order to pinpoint its location.

If the experts say the red line is in that spot, I am inclined to believe them. However, I don’t believe that even they know if the red line is exactly where the zipper will necessarily rip.

Another issue may be with the differing relative accuracies of the source material for the fault line before it was superimposed on the Google Earth imagery. I have seen many places where, it the line were moved a bit, it would fit the topography better.

For example, look at the location of the fault line here at the back of the Claremont Hotel. The location of that trench (in blue) is too close to the back of the hotel. In fact, it’s almost under it.

Claremont Hotel Rear Google

If you take a look at this photo of the same scene as taken from the stick pin vantage point. the fault line is likely a bit to the left, closer to the bank. 

Claremont Hotel Rear

That’s little consolation for the guests though if the fault rips open there. The hotel’s going to fall down anyway, and then catch fire.

We already had the Loma Prieta Earthquake in 1989. Didn’t that relieve the tension, making another big earthquake unlikely for a very long while?

Not on the Hayward Fault it didn’t! The branch of the San Andreas Fault in the Santa Cruz mountains is about eighty miles from the Hayward Fault in Berkeley. In fact, there is recently discovered evidence that a slippage on one fault may actually INCREASE the strain on another one parallel to it.

For example, scientists postulate that the 5.6 earthquake on the Calaveras Fault last October near San Jose may have increased the strain on the Hayward Fault farther north.

Take a look at this map and try to imagine the Pacific Plate twisting slowly around anti-clockwise in a north-west direction. Think what happens each time one of those faults breaks. You can easily see that the pressure on the next fault over could just as easily increase as decrease. Map courtesy of USGS.

 Bay Area Faults

Posted by: walkingthefault | February 24, 2008

Will it Rip Open Like a Burst Zipper?

The traditional picture people have in their minds of great earthquakes is of huge cracks opening in the ground, and cars and people and buildings falling in. Some people even think that California will be demolished and fall off into the Pacific Ocean. That may be the wishful thinking of some in middle America, especially in the “red” States, particularly with Berkeley in mind, but I don’t think it will be quite that bad. Let’s look at some facts.

Firstly, the study of the science of Plate Tectonics tells us that the Pacific Plate, which abuts the North American Plate, is moving inexorably in a north-west direction at a rate of about 3-6cm per year. The boundary between the Pacific Plate and the North American Plate runs through the Bay Area, and manifests itself in massive cracks in the earth such as the San Andreas, the Hayward, and the Calaveras faults. These cracks alternately jam up, and then suddenly give way, so that north-west drift is not a nice smooth ride.

The last big quake on the Hayward Fault occurred 140 years ago in 1868, with an estimated magnitude of 7.0. Most of the actual slippage of the Pacific Plate, about four feet, occurred on the southern half of the fault, around Hayward, hence its name. Digging of trenches across the fault line reveals that the part through Berkeley and to the north remains jammed up solid.

Since roads and streets have been built in the last fifty years or so, fault creep has occurred in the southern part, which may have relieved some of the strain. You can see the deformed curbs, sidewalks, and buildings where they straddle the fault. But there is little evidence of fault creep along the section through Berkeley, except across Memorial Stadium, part of which has moved about thirteen inches since it was built in 1923.

Codornices Park Playing Field

Do you see any evidence of the Hayward Fault, or any fault creep in this photo of the playing field in the southern part of Codornices Park? I don’t, none whatsoever. But it runs right through the center of the photograph. I often try to imagine it after the earthquake has wrought its havoc. Not only will we have lost the ball, but possibly a few of the players as well.

The last big earthquake in the Bay Area, Loma Prieta, occurred on October 17, 1989. 69 people were killed, 3757 were injured, and 12,000 people were left homeless. Most of the damage occurred far from the epicenter, which was in an unpopulated area of the Santa Cruz mountains. The Cypress Structure and Bay Bridge collapses were attributed to construction deficiencies, and the Marina District structural failures to liquefaction of fill, not because they were on, or anywhere near the epicenter or the actual fault line.

But in the Santa Cruz mountains, the ground certainly ripped open like a burst zipper, with a sideways movement of about 1.6 meters. Photo courtesy of USGS.

Loma Prieta Crack

You can see more photos of the zipper effect here.

The previous earthquake comparable to what is likely to happen on the Hayward Fault very soon was the Great San Francisco Earthquake of 1906. Anybody who has not read Simon Winchester’s Book, A Crack in the Edge of the World, should do so at this point, and then take a drive out to Olema in Marin County and look at the evidence. The burst zipper effect can be seen in the fences, roads, and lines of trees displaced by about 8.5 feet. Photo courtesy of USGS.

Fence Near Olema

As with the Loma Prieta earthquake though, and the last Hayward Fault earthquake in 1868, almost nobody lived there at the time. It’s a totally different story for the Hayward Fault today where millions of people live in homes and work in offices built right on top of the fault.

So, to answer the question as to whether the Hayward Fault through Berkeley will rip open like a burst zipper, one has to pose the question, why wouldn’t it? The buildings built on top of it aren’t going to glue it together! The Pacific Plate is moving, like it or not, and the timing points towards any day now. I do not think I am being unnecessarily alarmist. I do think though, that most people who live in the area are being inordinately complacent.

Posted by: walkingthefault | February 22, 2008

A Scary Picture

Nobody, even the most knowlegeable seismologist, knows whether the next earthquake on the Hayward Fault will rip open like a zipper, much less where that scenario would occur. But what we know for certain is that the fault, or at least parts of it, did rip open 140 years ago as the ground to the west of the fault shifted northward by about eight feet. And, remember that 140 years is the average interval for the last five quakes on the fault.

The exact location of the fault is not clearly visible, except to the trained eye. It has taken the digging of a number of trenches to pinpoint exactly where it is. The past 50 years of road construction, building, and landscaping have pretty much wiped out all evidence of it. Take a look at the Google Earth image below. If the red line weren’t there, could you see evidence of the fault? You can’t even see it when walking on the ground. Would anybody in their right mind, knowing what we do today, build a tots’  playground right on top of the fault? Well, take a look at the yellow stick pin in the middle of the image.

That’s the tots’ playground in Codornices Park. I don’t believe the City had the intention of building a kiddies’ playground right on top of an earthquake fault. Probably, the exact location of the fault as shown by the red line became clear long after the playground was built. Let’s take a look at the playground as seen on the ground.

Codornices Tots Playground 

Do you see any sign of an active earthquake fault in that picture? It’s probably right under that sandbox at the bottom of the blue slides. That’s my whole point here. Over the years, the evidence of the fault has been so well disguised that most people, particularly the Moms and Dads with their kids at this playground, have no idea it is there. Same with the people who live in the houses that have been built on the fault. Other than the little shakers we get in Berkeley every few months, with a magnitude of about 4.0 on the Richter Magnitude Scale, there is nothing that’s sufficiently in our face to make us be better prepared.

Don’t forget that the Richter scale is logarithmic. What does that mean? It means that a 5.0 is ten times bigger than the little 4.0 tremors that we often feel, and a 6.0 is ten times bigger than a 5.0, and a 7.0 (which is the minimum that seismologists think will occur soon) is ten times bigger than a 6.0. Ten times ten times ten is 1000, which how much bigger a 7.0 is than the little tremors of the past few months.  But it’s actually worse than that, because it is 31,000 times STRONGER, and it’s the STRENGTH of an earthquake that knocks down buildings. Check this out, and use the USGS Calculator to play with some numbers if you really want a sleepless night.

Posted by: walkingthefault | February 20, 2008

The First Walk – A Four Year Odyssey

I am almost finished with walking every street, path, lane, and stairway in Berkeley, California. I started in 2004 when I retired from EBMUD. I am not the first person to do this. Jennifer English finished in December 2007, even though she started after I did. But then, she’s a lot younger, and probably fitter too. You can read all about her experience at Walking Berkeley.

I started the walks when I retired from East Bay Municipal Utility District in May 2004. I had been very ill for a number of years, but I loved my work so much that I hung in there. But I knew that if I didn’t kick back and start to relax, and get as fit as I possibly could, I’d be dead within a short time. So I set out to smell every rose in Berkeley.

The first day I could barely walk two blocks without gasping for air. But I persevered, a little bit further every day, and got up to about a mile within a couple of months. Then two miles. Then four. I didn’t go every day. Maybe three or four times a week.

Just like Jennifer, I marked my progress on the beautiful map published by the Berkeley Path Wanderer’s Association. I didn’t find out about that organization and their map until I had pretty near finished walking all of the flatlands, so I had to go back and walk along many of the paths and trails that I had missed.

Berkeley Path Wanderers Map

After I had finished about half of Berkeley, it got too much to walk to my starting point every day, so I would drive my car to a strategic location, park it, and start my walk from there. That was especially helpful when I started up in the Berkeley Hills, because you don’t want to have to do a three mile walk up steps and hills when you have just walked three miles just to get there from home! Plus, it gets boring walking the same streets every time. But Jennifer did the entire City of Berkeley from home, because she doesn’t have a car. I don’t know how she did it!

The past year has been spent entirely in the Berkeley Hills, with much of it up and down the stairways and lanes that connect the various areas at different elevations. The views are spectacular. Every time you turn a corner there is something new.

View of Mt Tam Through Tree

But there is a dark side. The more I walked, the more I thought about, and read about, earthquakes in the Bay area, and the coming earthquake on the Hayward Fault in particular. And it’s not only the fault that is the primary danger.

Do you remember the Oakland Hills Firestorm of 1991? Many areas in the Berkeley Hills are ripe for such a disaster, with wooden homes perched on the edge of canyons, roofs covered in dead vegetation, and surrounded by flammable eucalyptus trees. It’s an ideal setup for a devastating firestorm, possibly set off by the fires that will result from the earthquake.

As my walk of every street in Berkeley wound down, and I knew I had only a few miles to go, my thoughts turned to what I should do next. I knew it had to be more walking. I had to keep fit. Should I do another City? Other than San Francisco (which is a bit too ambitious), I knew that nothing could match Berkeley, and the Berkeley Hills in particular, for sheer beauty.

Codornices Creek Falls

The answer was obvious. I plan to walk every street, pathway, and lane alongside or crossing the Hayward Fault in Berkeley, just like I did before, but this time studying and documenting what I see. Some of it is not going to be pretty. The first time around I saw decaying buildings, abandoned cars with tanks probably half full of gas, piles of dried out vegetation and logs, and garbage spilling out of their containers. It’s not all neat, well-kept, manicured homes occupied by affluent people.

Posted by: walkingthefault | February 18, 2008

Walking for Health

For an older person, walking is the best thing you can do for your health. Don’t even think about going to the gym, with its treadmills and stairmasters, and weird machines that exercise muscles you have never even heard of, let alone use. That’s absolutely boring! Walking is all you need. And if flat terrain is not enough to get the heart and lungs going, get up in the hills and climb a few of the stairways, like the Maryland Steps pictured here.

Maryland Steps

I am not a doctor, or an expert in fitness. But I have had more than enough illness in my life to know how much walking has benefited me.

I had polio as a child, at age ten. It affected my back and leg muscles. Fortunately not the lungs. After a year in a wheelchair I had to learn to walk all over again, using different muscles. When you see me walk, you may even burst out laughing. Remember Monty Python’s Ministry of Silly Walks from the 1970’s, with John Cleese? I walk sort of something like that. But I get along the street, and that’s what matters.

In 1995, when I was 52, I had a couple of mini-heart attacks, requiring angioplasty to open up the arteries. Then the mitral valve started to fail. In 2000 I had the mitral valve repaired, with excellent results, but a disastrous aftermath. I contracted Methicillin Resistant Staphyloccus Aureus (MRSA) before it became fashionable, in the sternum, where they had wired my chest shut after the heart operation. It went on a rampage, and no amount of digging and scraping and flesh removal would stop it. After four operations I was a day or two away from death, when they decided to do something drastic. I signed the papers not knowing whether I would ever wake up.

With an incision going from my groin to my throat, they removed my sternum, the front part of my ribcage, and all of the flesh in the front of my chest which was infected, leaving a hole about eight inches in diameter and two inches deep. They built a new chest wall using some of my abdominal muscles, and by means of plastic surgery and lots of stretching, managed to find enough flesh and skin to cover the opening. The whole operation took about 10 hours. I was on intravenous vancomycin for a month in the hospital, and then for two more weeks at home. But the infection was vanquished, and I lived to tell the tale.

Four months later I was back at work. Over the next couple of years, multiple hernias occurred where various abdominal components migrated up into my chest cavity, and I had to have a couple more operations to try to fix that. They’ve done pretty much all they can for me, so now I have to live with this large lump of whatever it is protruding from the middle of where my chest used to be.

Many men have a beer belly. I am the proud owner of a beer chest. Because there is no sternum to hold it down, my heart has migrated up to the top part of the chest, and beats away merrily just below my throat. For a while I wore a chest protector like a hockey player, but it got to be too cumbersome, so I gave it up.

During all that time, the electrical system in my heart pretty much gave up, and I was on drug after drug to try to control the fibrillation. Then I started getting asthma attacks. After four more years at a pretty stressful job I decided to retire, in 2004. On my first day of retirement I started walking, a little bit more every day until I was up to four miles. The only time I couldn’t do the distance I wanted was if the heart was out of rhythm, because of the lack of oxygen, or if I was having an asthma episode.

But I kept at it, and got fitter and fitter. The asthma dwindled to the point where I gave up all of my inhalers. Then I started the more difficult part of Berkeley, in the hills with all the steep grades and stairways. The arrhythmia got worse though, and my doctors decided to put me on a drug of last resort. I had to spend a week in hospital undergoing tests to see if I could tolerate the drug, and that’s when they found out that my heart kept stopping at night, sometimes for 30 or 40 seconds at a time. Fortunately it always started up again spontaneously, but they think it had been going on for quite some time. That’s kind of scary, because I live alone at home. So they wouldn’t let me out of there until they had implanted a pacemaker. So now, every time my heart stops, which is several times a night, the pacemaker kicks in and restarts it.

Just two days after getting the pacemaker, I was back up in the hills, dragging myself up the stairways. Ten steps at a time, then turn around and rest and enjoy the view. Then another ten steps, and another rest. It took me another year to finish the hilly areas, and I am now almost done. Only three more miles to go.

What a journey. I’ll be done just before my 65th birthday in March 2008, ready to start the next project of walking the Hayward Fault in Berkeley.

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