What's the Most Awesome Thing You've Ever Seen? Musing on Solar Eclipses, Part 1

Totality of the solar eclipse of 1991 from San Jose del Cabo. The corona, an aura of plasma and gases, is only visible during totality. Photo by Dr. William Luebke.

There is a major celestial event coming up next month, a total solar eclipse that is going to sweep across a wide swath of North America. I'm here to say that if you can, make the effort to see it. Why? It's a truly unique experience that has mystified (and terrified) humans during our entire existence. Seeing a partial eclipse is interesting. A glimpse of a total eclipse is truly awesome. I can't make it this time, but I have seen two of them in my life, and I want to relate if I can just what a stunning experience it can be. So here is the account of my first experience in 1991. This is from a post I wrote in 2017:

What's the most incredible thing you experienced? 

 
There are lots of answers to such a question, and many different contexts and meanings. I had an abrupt reminder tonight of one of the most incredible things I ever took part in. We're putting in new carpeting (no, that's not the incredible experience), so I've spent the week organizing 26 years of accumulated papers and books to clear the floors throughout the house. It's as much trouble as moving, only there's no truck to stuff everything in. I was close to finishing when I got into a cabinet that had been blocked by other boxes for literally years. There was an old photo album. I opened it and was immediately transported back to 1991 when I experienced a total eclipse of the sun at the tip of Baja California in Mexico.

The "diamond ring" effect just before totality as the last of the sun's disk disappears behind the moon. Solar prominences are jets of gas shooting from the sun's surface. Photo by Dr. William Luebke

The 1991 eclipse was going to be visible from mainland Mexico, the tip of Baja California, and Hawaii. I was in my third year of teaching at Modesto Junior College, the new guy (needless to say, I'm not the new guy in the department anymore; I'm actually the senior member). Our astronomy professor, William Luebke, had made plans to fly to Hawaii for the event, but I found out that a relative (the mother-in-law of my sister-in-law) kept a condominium in San Jose del Cabo that she was willing to let us use. We jumped at the chance. All we had to do was get there. There were five of us and flights were expensive, so we decided to borrow a school van and make the 900 mile drive to the tip of the peninsula.

The drive was quite the adventure, and if I can locate the slides and scan them, I will perhaps tell the story. But we made it, and settled in for a few days to prepare (and get sunburnt while snorkeling). We selected what appeared to be an abandoned condominium plot and set up shop.

Who IS that young man?

The hillside was perfect, commanding a twenty mile long view of the coast. Soon others gathered, including an entire busload of Japanese astronomy enthusiasts who said they had rented the entire plot for themselves. After a few minutes of delicate negotiations, they allowed us to stay.

The length of totality was going to exceed four minutes, one of the longest eclipses of the century. We had three or four telescopes with us, so Dr. Luebke could concentrate on photographing the entire event, while I and Mrs. Geotripper could work with a telescope of our own that we shared with the many people on the hillside. During totality, thirty or forty people were able to take a quick look.

The eclipse was unlike anything I had ever seen in my life. In the hours before totality (which happened around noon), the air grew stiflingly hot, over a 100 degrees. The skies were almost free of clouds, and the sunshine was blindingly bright. The moon started to move across the disk of the sun, and we had quite a bit of time to watch the passage. Before totality, the sky remained bright. But then the last flash of the "diamond ring" effect took place and the sky suddenly darkened.

Not just darker. Dark. Stars and planets suddenly became visible, and the temperature dropped 15-20 degrees. Looking at the sun without needing glasses, I had little trouble appreciating the meaning that the ancients applied to eclipses. It was otherworldly; I almost found myself chanting for the dragon to release the sun from its prison.

Yes, the picture below was taken with a flash. It was that dark. Then it began to end. Bailey's Beads, the first dots of sunshine, broke through canyons and mountain passes on the surface of the moon, and the sky turned bright again. In a few more minutes, it was over. We packed up and headed home the next day (a whole other adventure).

At the time, we knew that the next solar eclipse that would be accessible to us would not be until August of 2017. It seemed such a long time into the distant future. I had no idea the many changes that would take place in my life, but suddenly it is upon us, on August 21. The path of totality is shown on the map below. If you have any chance at all, make your way and have a look. It is one of the most astounding sights you will ever see.

By the way, it turned out that Hawaii would not have been a good idea. Thousands of people flew there to see the eclipse, but low clouds obscured the skies and the only people who saw it were at the observatories beyond the end of the closed road on Mauna Kea. We were incredibly lucky to have had perfect weather in Baja.

It turns out that I had a second great opportunity to see a total eclipse in 2017. Read about soon in Part 2

What's the Most Incredible Thing You've Experienced? Memories of Baja in 1991 (and looking forward to August 2017)

Totality of the solar eclipse of 1991 from San Jose del Cabo. The corona, an aura of plasma and gases, is only visible during totality. Photo by Dr. William Luebke.

What's the most incredible thing you experienced?

There are lots of answers to such a question, and many different contexts and meanings. I had an abrupt reminder tonight of one of the most incredible things I ever took part in. We're putting in new carpeting (no, that's not the incredible experience), so I've spent the week organizing 26 years of accumulated papers and books to clear the floors throughout the house. It's as much trouble as moving, only there's no truck to stuff everything in. I was close to finishing when I got into a cabinet that had been blocked by other boxes for literally years. There was an old photo album. I opened it and was immediately transported back to 1991 when I experienced a total eclipse of the sun at the tip of Baja California in Mexico.

The "diamond ring" effect just before totality as the last of the sun's disk disappears behind the moon. Solar prominences are jets of gas shooting from the sun's surface. Photo by Dr. William Luebke

The 1991 eclipse was going to be visible from mainland Mexico, the tip of Baja California, and Hawaii. I was in my third year of teaching at Modesto Junior College, the new guy (needless to say, I'm not the new guy in the department anymore; I'm actually the senior member). Our astronomy professor, William Luebke, had made plans to fly to Hawaii for the event, but I found out that a relative (the mother-in-law of my sister-in-law) kept a condominium in San Jose del Cabo that she was willing to let us use. We jumped at the chance. All we had to do was get there. There were five of us and flights were expensive, so we decided to borrow a school van and make the 900 mile drive to the tip of the peninsula.

The drive was quite the adventure, and if I can locate the slides and scan them, I will perhaps tell the story. But we made it, and settled in for a few days to prepare (and get sunburnt while snorkeling). We selected what appeared to be an abandoned condominium plot and set up shop.

Who IS that young man?

The hillside was perfect, commanding a twenty mile long view of the coast. Soon others gathered, including an entire busload of Japanese astronomy enthusiasts who said they had rented the entire plot for themselves. After a few minutes of delicate negotiations, they allowed us to stay.

The length of totality was going to exceed four minutes, one of the longest eclipses of the century. We had three or four telescopes with us, so Dr. Luebke could concentrate on photographing the entire event, while I and Mrs. Geotripper could work with a telescope of our own that we shared with the many people on the hillside. During totality, thirty or forty people were able to take a quick look.

The eclipse was unlike anything I had ever seen in my life. In the hours before totality (which happened around noon), the air grew stiflingly hot, over a 100 degrees. The skies were almost free of clouds, and the sunshine was blindingly bright. The moon started to move across the disk of the sun, and we had quite a bit of time to watch the passage. Before totality, the sky remained bright. But then the last flash of the "diamond ring" effect took place and the sky suddenly darkened.

Not just darker. Dark. Stars and planets suddenly became visible, and the temperature dropped 15-20 degrees. Looking at the sun without needing glasses, I had little trouble appreciating the meaning that the ancients applied to eclipses. It was otherworldly; I almost found myself chanting for the dragon to release the sun from its prison.

Yes, the picture below was taken with a flash. It was that dark. Then it began to end. Bailey's Beads, the first dots of sunshine, broke through canyons and mountain passes on the surface of the moon, and the sky turned bright again. In a few more minutes, it was over. We packed up and headed home the next day (a whole other adventure).

At the time, we knew that the next solar eclipse that would be accessible to us would not be until August of 2017. It seemed such a long time into the distant future. I had no idea the many changes that would take place in my life, but suddenly it is upon us, on August 21. The path of totality is shown on the map below. If you have any chance at all, make your way and have a look. It is one of the most astounding sights you will ever see.

By the way, it turned out that Hawaii would not have been a good idea. Thousands of people flew there to see the eclipse, but low clouds obscured the skies and the only people who saw it were at the observatories beyond the end of the closed road on Mauna Kea. We were incredibly lucky to have had perfect weather in Baja.

California is Going to Fall into the Sea! Quiz Question #1

Comic art courtesy of Zeo

Thursday, while preparing for my public lecture on earthquakes and California, I blogged a short true-false quiz that I was going to present to my audience. We had a great time on Friday night, I think. 300 community members came out on a Friday night to see a science lecture! Anyway, here was the first of the questions:

California is going to fall into the sea: true or false?

This is one of those persistent statements about California earthquakes that everyone "knows", even if they live in New Jersey. I had a pretty savvy audience; they had a better than average understanding of earthquakes, and answered with the obvious answer: false.

I then offered up the correct answer:

True!

In fact, not only is it going to happen, it already has.

Check out the NASA photo above. When we speak of California, we often forget that most people are only thinking of one part of California: Alta California (upper California). The image above reminds us that Baja ("Lower") California is also part of our geography. And Baja has already fallen into the Pacific Ocean, in a reasonable interpretation of the statement. Baja was once connected to the Mexican mainland, and has been a peninsula for only the last four million years or so. It is the beginning of a massive rift that will ultimately tear Alta California apart, and send it traveling northwest at all of two inches a year. The two inches per year will actually be taken up by large earthquakes shifting the landscape 10-15 feet every century or so.

In 20 million years, the Dodgers and Giants will again be crosstown rivals (yes, I stole this joke from the DVD "Planet Earth"). In 70 million years, California may slam into the south margin of Alaska, pushing up another high mountain range.

Want to see how this happened? Tanya Atwater of UCSB, the plate tectonics pioneer who figured out the origin of the San Andreas fault, has a series of excellent animations available for download at this site. If you have a fast connection, try this one (50 mb).

Courtesy of Tanya Atwater. See the animation here.

If you have a slower connection, this animation is 20 mb. Both animations show the complex interactions of the continental margin, with some parts being rotated, and others moving northwest along the San Andreas. And Baja California opening up to form a new seaway, the Gulf of California.

So indeed, it could be a good idea to buy up some property in the western Mojave Desert to be ready for your oceanfront views...in ten million years...if you want to wait that long.

What? You thought the question was about California falling into the sea during one earthquake? Really? Like the movie 2012? Not gonna happen. That's tabloid stuff. Aliens kidnapped me last week too.

5.7-5.9 Aftershock in Southern California

Big aftershock to the El Mayor - Cucapah Earthquake, just over the border in California, at 5.7 or 5.9 (awaiting confirmation from the USGS). It has been followed by more than a dozen aftershocks of magnitude 3.0 or higher. I would imagine it has been felt widely in southern California.

This is a good reminder to be prepared for the larger quakes to come. The San Andreas system has a great deal of accumulated stress that has to be relieved pretty soon.

Update: 5.7, after review by seismologists

Large Quakes in Gulf of California

Some large quakes within the Gulf of California a short time ago, with the largest preliminary magnitude at 6.9. They all happened within a few minutes of each other, so I expect the reported magnitudes will change as they sort out the data. The closest town is Santa Isabel in Baja California, 76 miles away. A 5.8 shock preceded the 6.9 event, which was followed by aftershocks at 6.0 and 5.0 magnitude.

The Gulf of California is the result of divergence, where Baja is sliding northwest and separating from the Mexican mainland. The movement of Baja is intimately related to motion on the San Andreas fault in California, as Baja and all the lands in Alta California west of the San Andreas are part of the Pacific Plate, which is shifting northwest at around 2 inches a year.

It's a good reminder that California is earthquake country, and that enough stress has built up on different sections of the San Andreas fault to produce major quakes. You can read lots more about earthquake hazards at http://earthquake.usgs.gov/.