Tuesday, August 23, 2016

The Hawai'i That Was: Watching the Destruction of the Islands in Real Time

The Big Island volcanoes of Mauna Kea (left) and Mauna Loa (right), as seen from the summit of Haleakala on Maui

Geologists have at their fingertips the closest thing to a working time machine that exists on planet Earth. We can't travel to the past, of course, but we can decipher past happenings by working out the sequence of geological events. But with the Hawaiian Islands, we have a different kind of time machine. We can predict the future of the Big Island.

The Hawaiian Islands are an example of an active hot spot, an enigmatic place in the Earth's mantle that is much hotter than surrounding regions. The hot spots produce tremendous amounts of basaltic lava that erupt onto the ocean floor, and the constant eruptions result in the formation of the gigantic shields like Mauna Loa and Mauna Kea (top picture). Since the asthenosphere (solid upper mantle and crust) is in constant lateral motion, the volcanoes that grow on the hot spots are carried off, and ultimately become inactive. The former hot spot volcanoes don't end with Kauai and Ni'ihau. There are submerged former islands on the Pacific Ocean floor that extend all the way to the Aleutian Islands in Alaska. In the history of these islands and former islands we see the future of the Big Island of Hawai'i. It will be a history of destruction and loss.
Haleakala on the island of Maui
The Big Island is larger than all of the other main Hawaiian Islands combined. As has been mentioned in the previous posts on the the Hawai'i That Was, the island is composed of five distinct shield volcanoes, Kilauea, Mauna Loa, Mauna Kea, Hualalai, and Kohala. As one flies to Kaua'i, as we did during our recent trip, we passed each of these smaller islands, some well known, others not. They include popular Maui and Molokai, as well as Lana'i and Kaho'olawe.

Maui (above) includes two shield volcanoes, the immense Haleakala (10,023 ft - 3,055 m), and the lesser known West Maui volcano (5,788 ft - 1,764 m). A low valley separates the two volcanoes. Some might ask why there are only two volcanoes and not five, like on the Big Island. Why, indeed?
South side of Moloka'i
Moloka'i is likewise made up of two volcanoes, although the linear nature of the island hardly suggests any kind of volcano shape at all. The entire north side of the island is one continuous high cliff that originated when the half of the volcano slid into the sea in a gigantic debris avalanche. Another island composed of two volcanoes. Why is that?
North side of Moloka'i (I haven't been there so we have an aerial photo instead).
The island of Lana'i is what remains of a single volcano. The uninhabited island of Kaho'olawe is likewise the remains of an isolated shield. So what's with all of these small islands composed of one or two volcanoes, instead of a large single island like the Big Island of Hawai'i? An answer is to be found with a map of the islands that also shows the submarine geology
Lana'i
The four islands, Maui, Moloka'i, Lana'i, and Kaho'olawe, are spaced about as far apart from each other as the peaks on the Big Island. The intervening seas are very shallow, and one soon realizes that Mau'i and the other islands were in fact once a single island similar in size to the Big Island. The islands have been sinking slowly as they press down on the underlying crust and mantle. They were interconnected as recently as the last ice age.
So, on our flight from the Big Island to Kaua'i, we see the future of the Big Island of Hawai'i. As the volcanoes subside (measurements at Hilo suggest about an inch per decade), the single island will become a series of isolated islands. Erosion will tear away at their flanks, and gigantic avalanches will tear away large portions, spreading the debris across the deep ocean floor. What's nice about this? The degraded and eroded masses of rock in the islands of Hawai'i have turned out to be some of the most beautiful landscapes on the planet! In the next post, we'll arrive at the most eroded island of all, Kaua'i (our recent trip only covered the two islands; I may take up an exploration of Oahu and Maui later on).

Sunday, August 21, 2016

The Importance of a Geology Education: Reflections on a Horrible Disaster in Louisiana (and others to come)

Hey, everyone! Raise your hands if you think a geology course should be REQUIRED of all students! [crickets]. Yeah, I thought so.

Geology classes occupy a somewhat uncomfortable zone within the standard college curriculum. Biology and chemistry are stand-alone majors, but they also provide important support to nursing programs and related health industries. Physics and mathematics likewise support numerous majors. But then there's that list of geology courses: they provide a pathway into employment in such diverse areas as oil and gas development, mining, water resources, parks interpretation, and education. But the number of geology majors is generally small in relation to other programs. And few students are really ever required to take a geology or earth science course as part of a different curriculum, with the occasional exception of a liberal arts degree leading to a teaching credential. Much of the time, geology courses mainly fill the role of general education breadth requirements, one choice among many.

Is there an argument for making geology classes mandatory in a college curriculum? Sure, for one good reason: geology can kill you. Oh sure, biology can kill you, given that whole disease thing, and pandemics, and grizzly bears and mountain lions.  Mathematics and physics can kill you, but usually in the context of a geologic disaster (or standing in the beam of a particle accelerator). I state this in a perhaps humorous vein, but with the burgeoning population of our planet, geologic disasters are becoming more and more commonplace. People are being forced to live in environments that are more and more dangerous, and the geologic events themselves are becoming more intense. Hurricanes and other weather events are being intensified by higher temperatures in the oceans and atmosphere, for instance. Earthquakes are not getting bigger (unless one lives in an area where fracking occurs), but with higher sea levels in the near future, the reach of tsunamis will increase.
Artist: Mark Waters, a student in the very first class I ever taught.

How far do we look for examples? This week I am watching dozens of fires burning through hundreds of thousands of acres of California, destroying hundreds of homes. Entire communities have been gutted. The fires are being intensified by an unprecedented drought entering its sixth year (the Colorado Plateau is in the fourteenth year of drought). At least 300 buildings have been lost in the Blue Cut Fire, but I wonder how many people in the area realize they are also living on the San Andreas fault, or that many of the homes in Wrightwood (in the affected area) are built on recent mudflow deposits?

And Louisiana...what can one say about Louisiana? It was just a rainstorm. A catastrophic 1,000 year rainstorm that dropped something like 2+ feet of water from the sky in just a few days. Tens of thousands of homes have been severely damaged, and people have died. A 1,000 year storm...a storm that has a 0.1% of happening in a given year. And yet West Virginia also suffered a 1,000 year storm in July. And there have been others.

My entire train of thought on this topic happened because I came across some articles that stated that only around a fifth of the victims of this week's flooding in Louisiana had flood insurance. My first thought was to wonder how in the world, in Louisiana, that this could be the case? There are many reasons, mostly financial (this is not the richest part of the country). But there are many other factors, too, and lack of education has to be one of them. Of course, there is the Mississippi and other rivers that flood regularly. But there is also the rise of sea level, and the subsidence taking place in the Delta. There are the changes in the intensity and timing of hurricanes and other intense storms due to climate change. People don't understand the risk of living where they choose to live (or where they are forced to live by circumstances). It makes no sense to skip on the insurance.

I then thought of California, where of course people are richer and better educated (please note, this is sarcasm, not a statement of fact). It took a few moments to find that only 17% of the residents of our state are covered by earthquake insurance (I strongly recommend reading the entire article). It's not hard to live in denial about the very real possibility of quakes in many parts of the state, but seventeen percent! Earthquake insurance can be expensive, but consider just why that is: these companies are not in the business to lose money, and their actuarial tables are probably a better indicator of the chances of earthquake damage than almost any geologic map (mind you, it's geologists who help calculate the odds that are used in actuarial tables).

People who live in ignorance also live in great danger. No place in the country is without the threat of some kind of natural disaster. One cannot realistically prepare for a cataclysm if one doesn't know that the possibility of the event exists. Education is the key, and it should be part of the curriculum of elementary and secondary schools as well as college. Community awareness, whether through social media or broadcast media needs to come from sources that are responsible and rational. There is so much CRAP on the internet that anyone could be forgiven for a sense of confusion. One group of ignorant people above all others who need an education in geologic hazards are the politicians. Science is almost never an issue in political campaigns (politicians seem to think we need to be more concerned with saluting flags and where people relieve their bladders). We need leadership at all levels of government to support community education, and to start dealing realistically with geologic threats and climate change (instead of denying that they exist).

Saturday, August 20, 2016

River Otters Swimming in the Tuolumne River, Part II


Here's the second video I captured of the River Otters in the Tuolumne River this evening (the first was in the previous post). There seems to be a momma and two pups. Meanwhile, Mrs. Geotripper was capturing pictures of me acting like a kid, chasing otters (if you are worried, I was actually pretty far away from them).

River Otters Swimming in the Tuolumne River



I've had a real treat of a day. I took my usual morning stroll along the Tuolumne River, catching some decent shots of a Black-chinned Hummingbird, and the back end of a Raccoon (that's not a great picture, but it was the first raccoon I've seen on this stretch of river). Then, totally on a whim, Mrs. Geotripper and I decided to catch the sunset from a high point on the Tuolumne Parkway Trail where the river emerges onto the floor of the Great Valley. We saw some kind of movement in the water, and I realized I was seeing River Otters (Lontra canadensis). My impression is that it was a mother with two pups. It was only the second time I've ever seen them, and this time I thought to catch some video. Enjoy! I'll post a second video in a few moments.

Thursday, August 18, 2016

You've Read About Them: How About Seeing Them in Person? California's Volcanoes Field Studies, Sept. 22-26, 2016

Mt. Shasta, the second tallest and most voluminous volcano in the Cascades
I write so much about my travels around the American West and elsewhere, and some might wonder where I find the time. Well...I tend to have a group of students with me. Geology, perhaps more than any other science, is best learned in the field, and our school recognizes the importance of field experiences.
Lava Beds National Monument
The community college system in California is of course one of the best alternatives for beginning a college education, a gateway to transferring into universities, but we also recognize lifelong learning as a part of our mission. Education doesn't just end with a degree. Professionals in one career can benefit from courses in related disciplines as a way of improving their job performance, or advancing up the pay scale. And all citizens can benefit from becoming better informed on the political issues of the day, such as climate change, or energy development (pulling some examples from geology).
Medicine Lake, glacio-volcanic lake occupying a large caldera.
With this in mind, I wanted to let my Modesto-based readers know about some great field studies trips coming up this fall. On September 22-26, I'll be teaching Geology 185, the Geology of California's Volcanoes. We'll be exploring Mt. Shasta, Lava Beds National Monument, Medicine Lake Highland, and Lassen Volcanic National Park, as well as Castle Crags and McArthur-Burney Falls State Parks. We will be camping at Woodson Bridge State Park the first night, spend two nights at Lava Beds National Monument, and the last night at McArthur-Burney Falls State Park. There will be hiking and caving opportunities, and some simply incredible scenery among some of the youngest volcanic features in the western United States.
Jot Dean Ice Cave. The ice persists in the cave year-round.
If this sounds intriguing, you can find more information at http://hayesg.faculty.mjc.edu/Cascades_field_studies.html. California residents pay the normal tuition rate (2 semester units), but the rate is higher for out of state participants. The $90 fee for the course covers the van transportation and fees at the various parks and campgrounds. The students provide their own food (we'll have stoves and fuel). For my local readers, we'll have an organizational meeting on Thursday, September 8 in the Science Community Center at Modesto Junior College, room 326, at 5:30 PM. Contact me if you have questions.
Lassen Peak and Manzanita Lake. Lassen erupted in 1914-15, while Manzanita Lake formed behind a debris avalanche about 300 years ago.
This isn't our only field studies opportunity! Watch for other announcements soon.

What's Burning Up Tonight: The Blue Cut Fire in Southern California

Source: http://www.fire.ca.gov/general/firemaps
California is burning. Sometimes, the fires are burning in unfamiliar places, places we've never visited. Logically, we know they are tragedies, that people are losing their homes, that beautiful forests are disappearing, but there's nothing quite like having a familiar place go up in flames.

Fires are part of the natural landscape, an outgrowth of a Mediterranean climate where no rain falls for six months out of the year. Plants and animals are adapted to fires. But things have changed, and some of the fires have become terrifying disasters. First of all, the growing population is expanding into ever more dangerous terrain, places that burn regularly, whether developed or not. But second, the effects of global warming are intensifying droughts that have left most of California dry and vulnerable.

The Blue Cut Fire is burning in an area I know well. I grew up at the foot of Lytle Creek and Cajon Pass, and have traveled over the pass perhaps hundreds of times over the years. The fire exploded in one day to more than 25,000 acres, and conditions offer little hope of any type of containment very soon. An unknown number of structures have already been destroyed, and an unprecedented 35,000 houses are threatened in places like Wrightwood, Phelan, and Lytle Creek. Something like 80,000 people have been evacuated. I hope and pray that it will be contained and controlled soon with a minimum of damage.

I wrote about the region a couple of years ago. Lone Pine Canyon is in the middle of the area that is burning, so the places seen in these pictures will be looking very different now. What follows is my post of March 31, 2013:

The Other California: Getting a Good Look at California's Faults

The San Andreas fault in Lone Pine Canyon near Cajon Pass in Southern California. Photo by Mrs. Geotripper

If there is anything that people know about California, it's the San Andreas fault. In a vague sense anyway...California has a lot of earthquakes that many people assume happen along the San Andreas (most don't), that there are occasional BIG ONES that happen on the fault (some of them, but not all), and if popular culture as expressed in movies like the original 1978 version of Superman reflects common knowledge, no one knows where it is or what it looks like (oh, and California is going to fall into the sea).
Still, the San Andreas is a fundamental part of the structure of California, and it is indeed capable of causing a great deal of seismic havoc, with some parts of the state considered at a high risk of moderate to large earthquakes. If one is curious about seeing the state's most famous fault line, there are a great many places to explore it, some in surprisingly visible locations. We are exploring one of them today in a segment of my "Other California" blog series.

Thousands upon thousands of cars follow Interstate 15 daily across Cajon Pass on their way to Las Vegas or their jobs in the L.A. Basin. I imagine few of the drivers know they are crossing California's most famous fault just a few miles north of the Interstate 15/Interstate 215 above San Bernardino. For a few moments, travelers are treated with a spectacular view up the linear track of Lone Pine Valley (the picture at the top of today's post shows the view, taken at 65 mph). I explored the lower end of Lone Pine Canyon and the "mysterious" Lost Lake (really not mysterious) in a post several years ago (click here to see it), but a weekend or two ago I had a chance to explore the upper end for the first time in a few decades.
The Mormon Rocks (or Rock Candy Mountains) expose the 18-20 million year old Cajon Formation. Interstate 15 climbs towards Cajon Pass on the skyline.
The road through Lone Pine Canyon takes off from Highway 138 about a mile west of the junction of 138 and Interstate 15. The road climbs through some beautiful exposures of the Cajon Formation  (the tilted exposures of the arkosic sandstones and conglomerates are called the Mormon Rocks or the Rock Candy Mountains; I've written about them before). The rocks have been tilted and folded due to their proximity to the San Andreas fault. The road surmounts a low pass and drops into Lone Pine Canyon.
The San Andreas fault is not a single break, but is instead a half-mile wide system of different slices of crust. Constant shearing over the last few million years by fault motions has left the rock fractured and easily eroded, forming the distinct linear valley of Lone Pine Canyon.
The series of fault blocks have formed a series of benches and scarps on the southwest side of the canyon, and a few offset channels are easily seen in the chaparral-covered hillsides (above).
Approaching the upper end of Lone Pine Canyon, we can see an odd hill in the middle of the valley. Looking at the steep slope to the right, it is apparent that we are looking at a rather large debris avalanche, caused no doubt by an earthquake along this stretch of the fault (above). The road skirts the lower end of the slide, confirming the nature of the hill with the broken and brecciated rock (below). There are plenty of candidates for the causative event; major earthquakes happened along this stretch of the fault in 1857(info here), 1812 (info here), and as many as a dozen other times in the last 1,500 years. There is a distinct warning in the earthquake history for this stretch of the San Andreas: the recurrence interval of large quakes is just over a century but it has been more than 150 years since the last major event.
The road reaches the top of the canyon, and a short walk along the ridge at the summit provides a spectacular view back down Lone Pine Canyon towards Interstate 15, and the two largest mountains in Southern California, San Gorgonio Peak and San Jacinto Peak. The fault passes between them on the way to Palm Springs and the Salton Sea.
 There is a large outcrop at the head of the canyon that exposes highly sheared rocks from the fault zone. The original rocks may have included the Pelona schist and granitic rocks but they are almost unrecognizable in hand samples.
But one thing is kind of cool: how often can you hold a major fault zone in your hand?
The road through Lone Pine Canyon ends in the village of Wrightwood, the subject of our previous post about a recurring mudflow originating in the Pelona Schist on the high ridges above. As if they didn't have enough to worry about...

The Other California is my continuing blog series on the geologically fascinating places in our fair state that don't always make it onto the tourist postcards.

Tuesday, August 16, 2016

The Hawai'i That Was: Pu'uhonua o Honaunau, the Place of Sanctuary That Might Not Be So Safe (Geologically)

Kealakekua Bay
I mentioned earlier in this series that cliffs aren't that common on the Big Island, with the exception of the Pololu and Waipi'o coastline. There is another cliff, though, and its formation has had a profound influence on the island's history, even though it took place long before humans arrived.

Large cliffs develop on the Big Island of Hawai'i primarily as a result of gigantic debris avalanches that carry a large portion of the island into the deep ocean, leaving behind cliffs and a scalloped coastline. The Alika debris avalanche did this exact thing about 120,000 years ago, with a runout of about 60 miles across the ocean floor. The slide produced a huge tsunami that dumped chunks of coral more than 1,000 feet above sea level on Lana'i (most tsunamis generated by earthquakes rarely exceed 100 feet in height). If such an event were to happen today, the effects would be unthinkably horrific. Luckily, they are rare, tens of thousands of years apart. There would presumably be many signs of an impending collapse (one would hope, anyway).
Hikiau Heiau at Kealakekua Bay
In terms of human interest, the slide produced a deepwater bay, Kealakekua, that was of great value to the native Hawaiians who colonized this coast. For several miles south, the coast was unusually flat, as subsequent lava flows filled out and formed sort of a delta into the Pacific. The amount of level land led to a high population density. Important archaeological sites are extensive, most notably at Kealakekua Bay State Historical Park, and at Pu'uhonua o Honaunau National Historical Park.

The park at Kealakekua Bay preserves Hikiau Heiau (above), a huge structure dedicated to the war god Ku, and Lono, the god associated with fertility of the land. It has been damaged by a number of tsunamis, but has been repaired and is still sometimes utilized for ceremonies.

The cliff at Kealakekua Bay is of special importance to native Hawaiians. It's called Pali Kapu O Keoua ("the forbidden cliff of Keoua"), and the various holes and caves in the cliff contain the bones of royalty. Such bones are said to possess great power (mana), and so great effort was invested in keeping their location hidden (I seem to remember reading that a trusted servant would dangle from a rope on such cliffs, and when he had hidden the bones, the rope would be cut and the servant would plunge to his death; an honor, I guess, but not a great job benefit).
One more moment of history has to be mentioned when exploring Kealakekua Bay. The small white tower in the middle of the picture above marks a small bit of property owned by the British government. It's called the Cook Monument, and it commemorates the "discovery" of the Hawaiian Islands for the first time by someone other than Polynesians. Captain James Cook and his crew landed here in 1779, and through a set of odd circumstances were greeted as gods. They spent a month interacting with the islanders, and left on good terms. A broken mast necessitated their return a short time later and things didn't go so well. Captain Cook was killed in a fracas over a rowboat. The Hawaiians treated his body as a royal, and his remains were hidden on the pali (although some "bits" were returned to the crew).

The effect of European contact cannot be overstated. While the arrival of western technology allowed King Kamehameha I to gain control of the entire island chain, forming the nation of Hawai'i, disease decimated the Hawaiian people (from as many as 1,000,000 to maybe 30,000). Just over a century later the island was taken over by corporate interests, before becoming a territory of the United States. Although the Polynesians had caused the extinction of native species through the introduction of invasive animals and plants, the process was greatly accelerated with the arrival of the Europeans.
Pu'uhonua o Honaunau
Life on Hawai'i was difficult enough, with the danger of volcanic eruptions, earthquakes and tsunamis, but in the years before European contact, seemingly small slights could get you executed. The high population of the islands required a highly regimented society to maintain order, and the principle of kapu included a long list of transgressions that could result in an instant death penalty. These rules involved how commoners could interact with royalty (stepping on ali'i's shadow, or touching him or his possessions), how they interacted with each other (men could not eat with women), and relationships with the land (fishing and logging regulations). If you broke kapu, even by accident, the death penalty could be immediate. In essence, a person had one chance to survive. There were sanctuaries, the Pu'uhonua, where one could be cleansed of their sin and receive forgiveness. The kapu breakers simply need to get there before their pursuers caught them. Pu'uhonua o Honaunau National Historical Park in part preserves one of these sanctuaries.
Heiau in the sanctuary at Pu'uhonua o Honaunau

It's hard to understand how kapu was tolerated, but in the context of religion, breaking of kapu could result in the punishment of the entire community, which was meted out in the form of storms, floods, earthquakes, tsunamis, and volcanic eruptions. It's a powerful impetus to stay in line if one thought they could bring destruction on their entire society. The strict adherence to kapu ended with the death of King Kamehameha I in 1819. His son the new king abolished the system by dining with his mother.
Fishpond at Pu'uhonua o Honaunau
The park in general is one of the best places on the islands to learn about Hawaiian culture. There are examples of heiaus, hales (houses), temples, and the pu'uhonua itself. There are some brackish pools that served as fishponds for the royalty.
There are interesting critters about as well. Some species of gecko may have arrived with the Polynesians, but others arrived much later. Eight species are present on the islands now. They are usually considered good luck, since they have an appetite for cockroaches and other pests.
The creature above is actually a sea urchin, the Shingled Sea Urchin. The modified flattened spines give the animal extreme stability in wave zones.

Pu'uhonua o Honaunau and Kealakekua Bay exude a sense of peace today, but they mask a turbulent past, both geological, and anthropological. If you are ever on the Big Island, they are two very interesting stops.