Friday, October 19, 2018

Upper McKenzie River/McKenzie Pass Guide

I promised a friend I would write up a self-guided tour of the area described in the title before this weekend, and if I'm going to get it done, it needs to be now. I don't have mileages, but I can post links that have lat/lon details embedded, and satellite imagery. Oh, and photos, of course. Oh, and links to old posts (maybe).

Before starting: Advice
  • Gas up before you leave Sweet Home (probably cheapest here or out at I-5). There's no gas for most of the trip until near the end.
  • Take food. There's a mom and pop burger joint at Clear Lake Resort, but it may be seasonal; I'm not certain it's open at this point.
  • Take layers and a windbreaker. It'll be a lot chillier at Pass levels, and it's often quite windy, so even if you don't need it, be ready to warm up.
  • I just checked: McKenzie Pass appears to still be open, which I expected, but for future reference, it's often closed at this point. It generally doesn't reopen until sometime in July.
Let's start with the Rte 34 crossing over I-5 as a beginning. Continue east through Lebanon, where 34 is rejoined by Rte 20, then on through Sweet Home. Stay on 20 until you come to McKenzie Junction. From I-5, I'm guessing this is a bit more than an hour, maybe 1:15 or thereabout. At the Junction with 126, there's a good pullout just after the turn. (Crosshairs on pullout here.) Walk back up the grade, west, along 20- there's a wide berm, and a great view of Three Fingered Jack.
Also, at this time of year, the vine maples are flaming red. Very evocative on the recent lava flow.
Speaking of lava flows, this is the first of many recent ones you'll see today. On the drive up from Sweet Home, you've been traveling through Western Cascades Volcanic rocks, which range in age from about 35 million to 5 million years old. Coming down this hill, you crossed from Western Cascades to High Cascades volcanics, which started about 5 million years ago, and continue to present. If I recall correctly, this flow is one of several from the Sand Mountain chain of cinder cones, at about 3000 years ago. More info here.

Head south on 126 to the Fish Lake parking area. Most of the year, this location is a meadow, but during late winter and spring melt and runoff, it fills with water and a native trout that resides in the creek most of the time occupies the lake. As it dries during the summer, they return to the creek. An interpretive sign describes their situation: apparently, they're reproductively isolated, and seem to be in the process of speciation- though that's my inference, and not explicitly stated on the sign.
Continue south, watching for signs to the Clear Lake Resort- it's a turn to the left, and always comes sooner than I expect.
A different lava flow than we saw at the junction blocked the McKenzie River about 3000 years ago. Most of the time, except for occasionally during peak melt-off, the lake is entirely spring fed, with no surface streams running into it. Nevertheless, the McKenzie River drains out of it, full-blown. There's a river's worth of springs under this lake! Also, you can see the trunks of trees drowned when they were inundated 3000 years ago!
Also, weird illusions... is this boat *in* the lake, or floating a few feet above it?
There are something like 18 lakes with the same name in Oregon, but to my mind, there's only one "Clear Lake." Note the drive in and out of the resort is south to north, so you passed the exit getting here, and you'll pass the entrance again once you leave. You have my permission to drive back through again. I mean, who could blame you? Continue south, and turn off (right) in a couple miles to Sahalie Falls.
According to the person who did her doctoral dissertation on the hydrology of this area, little or no water is added to the flow between here and Clear Lake, so this is a dramatic demonstration of just how much spring water flows into the lake.

Continue a few miles south to the Koosah Falls turn off, then drive in a ways to park. This is a frustratingly difficult waterfall to get a good view of, but there is a view area along the southern loop of the footpath.
You can also see the brink from a viewpoint there, but you can't really see the falls themselves. The really interesting thing is all the springs coming out of the walls in the lower gorge.
Continue south on 126 to the junction with McKenzie Highway, 242, and turn east (left). This looks like it's about 14 or 15 miles from Koosah Falls. Head east on 242 to Proxy falls, and park in the pullout on the left. There's a nice ~1 mile loop trail to Lower and upper Proxy Falls. The lower falls are quite spectacular.
The upper falls aren't as grand, but they *do* offer a nice analogy for all the weird water goings-on in this area: They originate as springs above the cliff, fall over it, and the plunge pool sinks right back into the ground. I don't think this "stream" even has a name; it's only a few hundred feet long. Incidentally, this lava flow is from Collier Cone, up near the North Sister, and at only 1600 years old, is the youngest lava flow you'll see today.
Continue the loop back to your vehicle, then continue driving east. You're heading up a glacial valley that was incised into the High Cascades during the last ice age, and the road switches back and forth to climb up the headwall of that valley's cirque. It gets... hairy. Take it slow and easy- the road's in good shape, it's just kinda scary. You can see why they don't maintain it for winter travel, though.

When you come out on top of the plateau, the road straightens out, the trees are much more sparse, and the views open up. This is from the edge of the first lava flow you encounter on the roadside after you're up on the plateau.
It may not look like anything special, but this young volcanic landscape is why there are so many springs: hundreds of inches of snow fall up here every winter. When that snow melts, all the water just runs into the ground, then re-emerges as springs along the Upper McKenzie River. The almost entirely spring-fed nature of that section is also why the water quality is so stunningly high. Continue east toward McKenzie Pass. There are several pull-outs on the right, with nice views of the Sisters.

Then comes McKenzie Pass and the Dee Wright Observatory. This spot is an Oregon Gem, but I'm always surprised how few know of it.
The lower story is enclosed, and each of the windows faces toward a particular volcano. The labels under the windows aren't easy to read in some cases. But the upper story is open, and has a compass rose point out many visible peaks. If you have time and interest the trail out onto the flow has quite a few informative signs.

This is more or less the end, but you have a couple of choices here. First, continue east to Sisters, then Head back to Corvallis over 20 and Santiam Pass- more scenic, but longer. Second, you can turn around and head back on 242 to 126, then follow 126 to Eugene/Springfield, then take I-5 back north to 34. Shorter and quicker, but less scenic. Hope this was fun! Below, geologists in their preferred habitat.

Monday, May 29, 2017

Advice to an Eclipse Chaser

Saturday, I received an email from a stranger who reads this blog, and occasionally reads my tweets, asking for advice on where to watch the eclipse in Oregon. As I explain below, the issue at this point is not so much where to watch, but where to stay. I'm posting my response in hopes this might help others with their planning.

Dear -----,

Glad to hear you've been enjoying my geology stuff, and I think you'll find Oregon does not disappoint in that regard. However, my immediate reaction to your letter is that if you haven't got accommodations locked down, you're going to have a very difficult time finding an allowed camping spot (without spending a fortune) at this point. There have been stories since last fall about reservations already being full. I can't really make a recommendation, as I have no idea where there might be openings. Probably your best bet is to hunt around outside the path of totality, wake up early, and drive to a decent viewing site.

Other things to be aware of:
  • This will be peak fire season, and many areas will likely be closed due to extreme fire risk. [addendum: Keep an eye on fire reports, and avoid those areas. Keep in mind that downwind smoke will not enhance the experience. Also, keep an eye on weather forecasts.]
  • Eastern and most of Central Oregon is sparsely populated, and smaller towns are going to have a very difficult time meeting the needs of the thousands of people expected to descend on them- so carry as much of whatever supplies you may want/need as you can. My suspicion is that lines will be horrendous, especially the morning and afternoon of the event.
  • Marys Peak would be ideal, which is why I never entertained it as a viewing location. I was relieved to learn, a few weeks ago, that access would be heavily restricted, and all permits for driving there are long gone. (Imagine a health emergency when 10 miles of road is gridlocked. Imagine the road rage from people furious they can't see, and the inevitable legal issues that would follow. These are just a few of the reasons I eliminated the site from my choices when I first learned of the eclipse 9 years ago.)
  • I expect much if not all of the path in OR will be blistering hot, with clear skies and intense sunshine. Plan water and sunscreen accordingly. On the other hand, nights can be surprisingly chilly, so bring some warm clothes as well.
  • Expect traffic to be a nightmare.
  • In case you don't know, it's safe to look at the disk during totality, but NOT during any portion of the partial, unless you have optics that are explicitly sun-rated.
My bottom line is this: I expect that if you're doggedly persistent, and plan your travel times to be longer than you'd expect otherwise, you'll be able to get in on the fun. You should check in with the BLM and Forest Service offices to ask for advice, but I'm gonna guess they'll tell you much the same. On the other hand, I know that John Day NPS will offer free camping to volunteers, if that possibility is still open. It might not offer the very best location for viewing, but it might save a lot of work and disappointment. I feel pretty confident in saying that everything will come to a halt as the time approaches, so any volunteer duties will basically end for at least a few minutes.

Also, I have found this site, hosted on Google Maps, to be very helpful.

Other than the eclipse, though, I can certainly give you scads of pointers of what to see and do around and near OR, and specifically in the Steens/Malheur area and nearby areas in northern Nevada. Please let me know how you're coming into SE OR, and I'll bet we can work out a sweet itinerary.
Wishing you the best of luck in your travels!

Lockwood DeWitt

Thursday, September 29, 2016

Geo 902: Jefferson Looms on the Horizon

A last shot from Ochoco State Park: I turned around to face west, and there was a nice view of Mt Jefferson. I promise, it's right there, kinda behind the middle of the three electric poles in the middle of  the photo. It's not the darker, more visible one in the right middle.

I had forgotten Jefferson is the second tallest mountain in Oregon (after Hood). More basic information on the mountain can be found on its USGS page. It's also the Cascade Volcano that's most reliably visible from Marys Peak, and thus the one I've seen most often. I have climbed most of the icefield visible in this photo, but it got steep enough that, without crampons, I decided to stop and turn around.

Photo unmodified. September 7, 2016. ZoomEarth location.

Monday, September 26, 2016

Geo 901: Prineville, Oregon

Looking northeast from the Ochoco State Park Viewpoint, Prineville sits almost entirely on alluvium of the Crooked River. I don't have a whole lot geological to say about this photo, but I liked it. For more about the geology of the area, I commend yesterday's PDF link, which I found while fact-checking myself, to you. I skimmed over the field trip briefly, and for people who want details of the area, it's a great resource!

Photo unmodified. September 7, 2016. ZoomEarth location.

Sunday, September 25, 2016

Geo 900: Ochoco State Park

Looking a bit south of east from Ochoco State Park, we see a variety of rimrock basalts of varying ages. The one on the right has been named the Basalt of Meyers Butte, which has been dated at 5.42 +/- 0.11 Ma, and erupted west of this location. (Glad I looked it up: I had been under the impression these came from Newberry Volcano, which is way to the south.) This PDF (see page 4) has a very similar photo to the one above, with the various basalt units labeled, and a field guide going into great depth about the volcanic stratigraphy of the area.

There are numerous reasons I wouldn't live in eastern Oregon, but the views and excellent, less weathered rock exposures make it a favorite place to visit.

Photo unmodified. September 7, 2016. ZoomEarth location.

Saturday, September 24, 2016

Geo 899: Three Fingered Jack and Cascade Crest

I've been trying to find a name for the peak on the left-middle skyline; at 6200 feet plus, it must have a name. However, I've been unsuccessful. The rubbley and shaded area on the left is the quarry northeast of, and the base of, Hogg Rock, and TFJ is the peak on the right. My sense, when I was there, was that we were looking at the transition between an icefield and a valley glacier in terms of the valley landforms, and the Google topo map below seems to support that somewhat. The black dot is the approximate location where the above panorama was taken. The patch of blue on the map's lower left edge, above Route 20, is the east end of Lost Lake.
Directly south of Hogg Rock, and not pictured, is Hayrick Butte, another tuya, and Hoodoo Butte, a post-glacial cinder cone, and the closest ski area to the mid-valley region.

Panorama stitched in Hugin. Photos unmodified. September 7, 2016. ZoomEarth location.

Friday, September 23, 2016

Geo 898: Three Fingered Jack

From a quarry on the north side of Hogg Rock, the view to Three Fingered Jack is excellent. Three Fingered Jack is described on OSU's Volcano World page as a stratovolcano in the leading basic information, then in the first sentence as "a deeply eroded basaltic shield volcano." I don't know which it is, but I guess I'd lean toward shield rather than stratovolcano. The Oregon Cascades were heavily glaciated during the Pleistocene, and the fact the volcano is so deeply incised shows that it hasn't been active- or at least hasn't had any major lava-producing eruptions- since the end of the ice age. Mt. Jefferson, the next major peak north of it, shows the same style of faceted glacial erosion.

Route 20 winds around the west and south side of Hogg Rock, a tuya (a sub-glacial eruptive landform, where the lava erupted under ice), much too close to get any decent photos, and the rock here in the quarry seemed too nondescript to bother with. The best photo of Hogg Rock on this trip was the one I took at Lost Lake. As noted in the post at that link, the pass area burned a few years ago, killing many, many trees.

Photo unmodified. September 7, 2016. ZoomEarth location.

Thursday, September 22, 2016

Geo 897: A Last Glance at the Lost Lake Drain Hole

I'd say the hole is about 4-5 feet across, less than the 6 foot diameter reported in most of the stories I've read, and 2-3 feet deep. As I mentioned in the first post about this location, the layers of ash and lapilli are probably responsible for creating a tough and poorly permeable lake bed. It does seem likely to me that this is some kind of sinkhole, but I don't have any sense of what might have created the void that the rock collapsed into. The mafic lava flows in the area have enormous amounts of void space in their rubbly surfaces, and I don't feel that a lava tube is a necessary conclusion, though it might be the correct one. Perhaps someday we'll find out.

To put this in a broader context, if you're traveling across Santiam Pass, and you have a little time, this is well worth the rugged, pot-holey drive in (I'd say okay for smaller cars, just take it slow.) at least once. It's not something I'm going to feel I need to do every summer, but I'd like to visit in the late spring sometime, and given the new hole, it might be worth stopping every few years or so, to see if the area evolves further.

Photo unmodified. September 7, 2016. ZoomEarth location.

Tuesday, September 20, 2016

Geo 896: Drain Oregon!

Drain, Oregon is an actual town off I-5, south of Eugene. But these two holes actually help drain Oregon. With Gary for scale, you can get a sense of how large the holes are, and their relationship to each other.

Photo unmodified. September 7, 2016. ZoomEarth location.

Monday, September 19, 2016

Geo 895: Lost Lake

Looking more or less west from its newest "drain hole." The old one is just out of the frame to the right. It's an odd spot, even without the drains: the basin was almost certainly covered in glaciers during the Pleistocene, but more recent volcanic activity blocked the outlet. As I mentioned on Friday, much of this area is covered with very permeable lava flows. Rain and snow melt goes directly into the ground, to re-emerge as springs at Clear Lake and elsewhere along the Upper McKenzie River. Here, apparently, the tephra seen in Fridays post, and the lacustrine sediments visible in the sides of the hole above, create a less permeable cap and impounding the lake's water. I can't say what portion of the lake's summer water loss goes down these holes, and what infiltrates directly through the lake bed and into the underlying bedrock, but I doubt the holes account for all of it. That is, I expect the lake bed isn't entirely impermeable.

Route 20 runs through the notch in the horizon on the left, and along the south side of the lake.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Sunday, September 18, 2016

Geo 894: Lost Lake Has a Falling Out With Itself

The sediment forming the edge of the second hole appears to be more like lake mud and silt than the ash and lapilli in the first, older, hole. However, I didn't look all that carefully at the stratigraphy here- the same mud and silt (which appears to be more easily eroded) may have been removed over the years since the original hole opened up. In other words, given a few years of erosion, this hole may come to look the same as the old one.

Also, as you can see, this hole is still draining the lake in early September. We had our first significant rain of the season yesterday and this morning, and I'd bet the pass area got much more rain than we did down here in the valley. While the next week is forecast to be dry and very pleasant, it won't be too long before both holes are submerged again.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Saturday, September 17, 2016

Geo 893: A New Drain for Lost Lake

When I looked up from peering into Lost Lake's "drain hole" yesterday, Hollie and Gary had wandered over to another hole- this one still actively draining the edge of the lake. They had been up here the previous summer, and assured me it was new in the past year. Cool!

Many the the articles I've read since this spot hit public awareness have well over-stepped the edges of what we actually know about what's going on here. They've confidently claimed there's a lava tube here. The are tubes in the area, and that's certainly a possibility, but I saw nothing that I would say is good evidence of one here. The bottom of both holes are rubble-choked, and both are relatively shallow. Articles have claimed there are vast "underground rivers." This reflects a common misunderstanding about groundwater: most often (except in karst terrain) the water travels in pore spaces and fractures between the fragments that make up the rock or aggregate, rather than in one or more defined channels, which are intrinsic in the concept of "river."

To me, this type of reporting doesn't seem so much "sensationalist" as it does "poorly informed." I don't know that either is better or worse, but the latter seems more tolerable in my mind, since I can add corrections in posts like this. The former just exasperates me. The world we live in is an amazing and astonishing place. Reporters don't need to add fireworks, bells, and whistles to make it more so- in fact, that behavior distracts from the wonders in front of our faces.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Friday, September 16, 2016

Geo 892: Lost Lake's "Drain Hole"

The hole is both smaller and shallower than I expected, and at this time of year, well back from the water's edge. The lake bed appears to be composed of relatively thin laminae of ash and lapilli, and well lithified. This isn't surprising, given its location near the crest of the active section of the Cascades, but it isn't what I was expecting. Rubbly basalt and basaltic andesite dominate much of the central Oregon Cascades between our location here, along Highway 20, and McKenzie Pass along Rte. 242. However, my suspicion is that under these layers of tephra, the lava rubble is present; that would allow the water draining through this sinkhole to move to the water table, and, ultimately, re-emerge at Clear Lake.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Thursday, September 15, 2016

Geo 891: Lost Lake Basin and Hogg Rock

The basin the the foreground fills with water during late winter into spring, then slowly drains into the ground over the summer- there is no surface outlet. I've thought for years that Hogg Rock, in the back, looked like a tuya- a subglacial volcanic landform- in terms of its shape, and a couple months ago, I was informed by Adam Kent, a volcanologist at Oregon State, that it is.

Over the past year, there have been a number of stories in Oregon news sources about Lost Lake's "drain hole," starting with one in the Bend Bulletin. Even though I had never stopped here before, I was able to get a general sense of its location from the shape of the landscape in photos accompanying the articles. However Hollie and Gary had visited the site previously, so we didn't have to search it out. Nevertheless, my "general sense" turned out to be quite accurate. We're looking pretty much right at it, but from this angle, it's hidden in the grass and willows.

The countless dead trees on and around Hogg Rock were killed in a nasty fire a few years ago.

Photo unmodified. September 7, 2016. ZoomEarth location.

Wednesday, September 14, 2016

Geo 890: Saber-Toothed Nimravid and Trip Outline

Cast of saber-toothed Nimravid display along the Island in Time trail, John Day Fossil Beds National Monument, Sheep Rock Unit. Nothing for scale, but I think box is ~3 feet on the sides. In terms of representing the area, the above, to me, is perhaps the most iconic fossil photo of the trip
Interpretive sign associated with the fossil cast above. (Open pics in new tab for larger size and readability.)

I've got this written up, and I'm going to go ahead and post it, but I need to double check and clarify a few things in the outline below, so I may make some minor changes and expansions in coming days

Day 1 (Wednesday, Sept. 7): Travel to Dayville, Oregon, stops at
  1. Lost Lake to see "drain hole." There are *two* of them now.
  2. Gravel quarry on back side of Hogg Rock.
  3. Overlook viewing area, Prineville. (Whole trip was in OR.)
  4. Roadcut of Clarno Fm. near milepost 53 on Rte 126 (Folds, faults, leaves)
  5. Mascall, Picture Gorge Overlooks, 4 miles west of Dayville.
  6. "Home" for four nights: house rental in Dayville.
Day 2: Exploration of two of three John Day Fossil Beds National Monument Units, Sheep Rock and Painted Hills. Stops/hikes:
  1. Mascall Overlook to check out morning (vs. evening) light.
  2. Blue Basin, Island in Time trail. (Photos above)
  3. Foree, Story in Stone trail and Flood of Fire trail.
  4. Thomas Condon Paleontology Center. (Holy Cow! My head was swimming!)
  5. Visitor Center, Painted Hills Unit.
  6. Red Scar Knoll trail.
  7. Painted Cove trail.
  8. Lower Meyers Canyon- mostly to fritter away daylight until early evening at next stop. (Outside JD Fossil Beds NM.)
  9. Painted Hills Overlook Trail. (Wished we'd been there an hour later, but still awesome.)
Day 3: Return to Painted Hills Unit for morning light, then on to Clarno Unit, and Nut Beds in Fossil.
  1. Painted Hills Overlook for morning light. ( Not *quite* as spectacular as evening, but still...)
  2. Leaf Hill trail. (Meh)
  3. Caroll Rim Trail. (OMG overwhelmingly gorgeous! For n=1->infinity, repeat.)
  4. Drive to Clarno Unit, several roadside stops to puzzle out stratigraphy.
  5. Clarno Unit, Geologic Time trail and Trail of Fossils
  6. Fossil, OR High School, digging in famous Nut Beds- found some leaves.
  7. Return to Dayville through Sheep Rock Unit. Stopped to photograph Sheep Rock. (Lighting is poor midday.)
Day 4: Baker (ophiolite) and Izee (Crazy metamorphosed and folded seafloor sediments atop Baker) Terranes.
  1. Two stops in Baker Terrane on Rte. 395 just south of (City of) John Day.
  2. Five stops in Izee Terrane between mileposts 11 (I think- need to check) and 15 on Rte. 395.
  3. Return to John Day and explore ultramafics and associates of Baker Terrane from Forest Service roads (This had a number of stops, and is complicated. But a companion GPS'd 'em all, so I'll get better info.)
  4. Home.
Day 5: Return to Corvallis. Stops at:
  1. Smith Rocks State Park and a hike. I was too tired and sore to really enjoy this, misinterpreted a map, resulting in an extra mile or two of hiking, and lost my lens cap to the Crooked River. But better than I'm making it sound, plus I'd never been there before.
  2. Crooked River Gorge. A nice, easy amble, with a spectacular gorge 300 feet deep, and sheer basalt walls.
  3. Niagara County Park along N. Santiam River.
  4. Yay! Back in Corvallis.

Wednesday, August 24, 2016

Geo 889: Stranded Terrace II

A shot from nearby yesterday's, which zooms in a little closer to the small remnant of stranded terrace deposits. I like the framing of the foliage and old man's beard.

Photo unmodified. July 21, 2016. ZoomEarth location.

Tuesday, August 23, 2016

Geo 888: Stranded Terrace Deposits

Overlooking a small cove just north south of Sunset Bay, one can fairly easily spot the buff-colored layer of semi-consolidated sand, about six feet thick, overlying the tilted Eocene beds of the Coaledo Formation. It's a beautiful spot, and a nostalgic one for me. When I was young and hale, I clambered down into this cove a few times; there are some gorgeous sedimentary structures in the strata here. But at this point, with poorer balance and limited endurance, there's no way I'll be down there again unless a decent path is constructed. I have no reason to think that has been, or will be, done. The routes down were precarious, with tree roots and vines, mostly, as the only hand-holds, and the climbs back up were often scary, or worse if I had taken samples (one ten-pound block, in particular, comes to mind).

There's a modest fault running through the cove; this is particularly apparent in the ZoomEarth satellite image. I'm pretty sure the sandstone bed running from the middle toward the lower right is the same as the one on top of the tilted slab on the middle left.

However, the feature the sprang out at me on this trip was the isolated bit of terrace material on top of the anvil to the far right. There a tension between subsidence and uplift in this area. On a scale of millennia, there can be subsidence, as demonstrated by the dead tree stumps on the inner south shore of Sunset Bay. On a longer scale, tens of thousands to millions of years, terraces like this (and six more higher up tentatively identified) clearly show a pattern of tectonic uplift. That little pile of stranded terrace deposits will soon fall as the latest victim to the ongoing ups-and-downs of this area's coastal elevator.

Photo unmodified. July 21, 2016. ZoomEarth location.

Monday, August 22, 2016

Geo 887: Wave Refraction

As an ocean wave approaches shore, it reaches a point where the decreasing water depth causes it to slow and pile up. Wave frequency (number of waves in a period of time) remains more or less unchanged, but wavelength (distance between waves) is shortened, and amplitude (height between crest and trough) increases. Shortened wavelength and increased amplitude finally renders the wave unstable, and it breaks.

The seas on this day at Sunset Bay were quite calm, but the narrow opening to the bay at low tide meant that what waves were coming in off the ocean were well defined. Despite the curvature of the shore, you can see the waves are approaching it nearly perpendicularly across its length (despite the pesky botanical material in the way).

Photo unmodified. July 21, 2016. ZoomEarth location.

Sunday, August 21, 2016

One Year From Today

The blue line across the middle represents the mid-line of the August 21, 2017 total solar eclipse. The shaded area around that line represents the area of totality, where the sun's disk will be completely obscured for a period of time as the moon passes in front of it. The closer an observer is to the mid-line, the longer the sun will be obscured.

I've been excited about this for years; I've never seen a total solar eclipse. I've seen partials that were total or annular elsewhere, but I've never been in the path of totality. For viewing, all I really need to do is be awake and standing in view of the sun, but I'd like to get to a decent elevation. I understand that if you're in a spot with a good east-west vista, you can see the shadow of the moon approaching and receding before and after totality. In Corvallis, the umbral speed will be 1.310 km/sec, or 2929 miles per hour-- which is to say, the fastest predictable thing I will ever see. This interactive map (from which the above screen shot was taken) is the best resource I've found for planning, with extensive details about the event. Simply click the crosshairs on a point of interest, and a table of data will pop up, telling you everything you could want to know about the eclipse at that position.

I have some ideas about where to watch it, but I hope to have opportunities to do some scouting between now and then. It may be that I can get up to the Santiam Pass area and do geology for much of the remainder of the day. In the end, I suspect I'll play it by ear. This time of year, fires and smoke can muddle an otherwise glorious view. However, the chance of rain- or even heavy clouds- in mid-late August is next to nil.

Sunday, August 14, 2016

Geo 886: View of a Broken Shoreline

You can see (barely) the two beds from yesterday's photo behind Gary, and the fault in that photo is the nearly horizontal dark line extending east-west. Less obvious, but quite clear when you recognize what you're seeing, is a larger fault just behind him. The prominent sandstone bed behind Hollie is the same as the one on the far right side of the photo. If the offset on the closer fault is horizontal, and I'm not sure it is, it looks to be about 30-35 feet. Some three and a half years ago, I posted and annotated a shot of this same area, but looking approximately the opposite direction.

On that previous visit, in early March, the wind and chilly temperature combined to make not-so-pleasant conditions. On this visit, apparently, warmer temperatures and less energetic summer waves in July combined to deposit a couple inches of disgusting, sulfurous, black, slimy mud in certain areas of the intertidal zone. We had to walk through that to cross the larger foreground fault. I'm honestly not sure which "downside" was more unpleasant, but in both cases, it was well worth the discomfort. Though if I'd slipped and fallen in that awful mud, I have no doubt I'd prefer March.

Photo unmodified. July 21, 2016. ZoomEarth location.