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With all the construction going on around town, you’ll see lots of drill rigs taking geotechnical cores. This one was at work at 2330 Webster, where the Webster Alexan development will go. Just a few days earlier, a rig was collecting cores in the parking lot at 20th and Telegraph, slated to become one of […]

Seniors, Get Your Lifetime National Park Pass Now

Get your lifetime pass before the price takes a quantum leap! -- Read more on

After the Disasters that Formed the Crater Lake and Crooked River Calderas, St. Helens was Hardly a Blip...Right? Uh, Right?

2 months agoAcademics / Geology : Geotripper

Yup, perspective is everything. I've been going on for several posts about prehistoric volcanic eruptions that were pretty much unimaginable in their violence and destructiveness. The Crater Lake eruption took place 7,700 years ago, and put 15 cubic miles of ash into the atmosphere, covering much of the western North America. Show More Summary

Important San Pedro River Subflow Adjudication Ruling!

By Order dated July 13, 2017, Maricopa County Superior Court Judge Mark H. Brain (presiding judge in the Gila River adjudication) affirmed the most recent effort by the Arizona Dept. of Water Resources (ADWR) to delineate the lateral extent of certain hydrogeologic areas known as subflow zones in the San Pedro River watershed in southeastern Arizona. Show More Summary

What Could be Worse than the Crater Lake Eruption? A look at Smith Rock State Park in Oregon

2 months agoAcademics / Geology : Geotripper

Standing on the rim of the Crater Lake caldera, as we did in our last post, it is hard to imagine the scale of the catastrophe. In that event just 7,700 years ago, 15 cubic miles of ash was blown into the atmosphere, covering much of western North America with volcanic dust. Show More Summary

The smaller creeks of Leona Heights

Last week I lingered over Leona Creek, in the Leona Heights area, but there are three other streams in the land between Horseshoe Creek and Chimes Creek. I’ll label them on the watershed map from 1 to 3, putting the numerals where they enter culverts. Creek 1 passes through the old Crusher Quarry grounds, now […]

When Life Gives You a Single Point of View, Milk it For All it's Worth: Crater Lake in June

2 months agoAcademics / Geology : Geotripper

It never fails. I secretly control the incidences of drought and flooding in the western United States. How? By scheduling our summer field studies a full year in advance. The proof? Every time I schedule a Southwest trip, the climate changes to long-term drought, and it is a hot summer. Show More Summary

Hypothetical Earthquake Scenarios: A planning tool for civil authorities

USGS hypothetical earthquake scenario map tool. The US Geological Survey just released an online interactive map tool that showcases earthquake event scenarios for select faults in the contiguous U.S. Their objective: "to convey event locations, rupture areas, and shaking for hypothetical earthquake scenarios." This is a great idea. Show More Summary

Dealing with the Dangerous Rays of Death: Singular Solar Events I've Seen

3 months agoAcademics / Geology : Geotripper

Do you ever look at the sun?Some advice: DON'T LOOK AT THE SUN! You can destroy your eyes!Good, now that we have that out of the way, what is this post all about? The sun has been on my mind the last few days. I'm preparing for the final...Show More Summary

Liveblogging the Deluge: Is the Big-Boned Lady Singing? The Aftermath of the 2017 Flood on the Tuolumne River

3 months agoAcademics / Geology : Geotripper

The Tuolumne in August of 2015. This was a sick river overgrown with invasive hyacinth. Flow is about 200 cfs. Goodness sakes, are we still talking about that flood? Well, yes we are. It isn't quite done, although events this week are signaling the end, at least in some respects. Show More Summary

But Wait! THIS Summer isn't even over yet! Explore the Colorado Plateau, June 2-17, 2018 (Put it on your calendar now!)

3 months agoAcademics / Geology : Geotripper

North Rim of Grand Canyon National Park (yes, Gaelyn, we'll be on the North Rim, hope to see you there!) "Wait!", you are saying, "it's still the summer of 2017! Why are you talking about the summer of 2018?" It's a fair question, and the answer is predicated on an unfortunate truth: our parks are too small and too crowded. Show More Summary

The mine drainage of Leona Creek revisited

Over the years I’ve done a lot of poking around Leona Heights, the large hill looming over the south end of the Warren Freeway. You’d think I have a nice photo after all this time, but instead here’s a vertical view from Google Maps, terrain view. It shows the area between Horseshoe Creek, at the […]

Shingle Beaches: Pebble Paradises

Get to know shingle beaches in five easy sections! -- Read more on

Walking on Broken Glass, Literally: And what is slabby pahoehoe?

3 months agoAcademics / Geology : Geotripper

Some places on our planet are just not like anywhere else.Kilauea, on the Big Island of Hawai'i is one of the most volcanically active places on Earth, and very few parts of its surface are older than a thousand years, and most are much younger. Show More Summary

That sinking feeling: State-of-art technology at work on Arizona subsidence finds you’re not imagining it

Satellite-based tech employed by Arizona Water Resources has found more than 3,400 square miles of land subsidence in the state Arizona is sinking. Well, not all of Arizona, just certain groundwater basins in south-central and southern Arizona. Show More Summary

What the Heck is a Superelevated Lava Flow Anyway? 1974 Basalt Flow near Keanak?ko‘i Crater

3 months agoAcademics / Geology : Geotripper

Talk about catnip for a geologist... "Do Not Enter", "Stop Here", "Go no closer to the eruption", and "Roads and Trails Closed Beyond This Point". How could any self-respecting geologist ignore such signage? And yes, that is a volcanic plume emanating from a crater on the far right side of the picture. Show More Summary

High Water Across the West: Not at West Gate!

I was surprised when driving through central Nevada back in early May that things didn't really look all that green or wet, at least as compared to what I'd already seen in northern Nevada along the Truckee River, at Rye Patch Dam and the Humboldt Sink, at the Pitt-Taylor Reservoir and in Winnemucca, in Carlin Canyon, and at Honey Lake. Show More Summary

Rocks: A Handy Book for Tiny Geologists

Discover a fantastic book to give to kids as they explore the rocky world this summer. -- Read more on

Oakland geology ramble 4: Uptown to Montclair

This five-mile urban hike is more of a terrain-and-streams ramble than a bedrock ramble. It climbs over 700 feet, winding through the watersheds that freshen Lake Merritt and traversing some of Piedmont’s wildest land. Although I’ve walked the route both ways, I’ll present it here from west to east. The route goes from the 19th […]

How Foolish Can These People Be? The Treasure of our National Monuments

3 months agoAcademics / Geology : Geotripper

Let's make something very clear: these lands belong to the American people. They have always belonged to the American people, dating back to the time of statehood. There were attempts at times to give some of the lands away a century ago under the Homestead Act, but no one wanted them (not that anyone was asking Native Americans at the time). Show More Summary

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