Walker River Delta, Nevada: 1994-2007

Dynamic changes on the delta of the Walker River. I made this simple movie with Google Earth, Snagit, Picasa, and YouTube. Took 30 minutes total.
 
Trying to develop painfully obvious illustrations for the need to create easily updatable and distributable maps of dynamic geomorphic settings. This is part of my odyssey to convince people to share data; contribute data to a single database (or coordinated databases); number their units in depositional order; and accept the fact that geologic maps of active systems require continuous updates. 
 
Note: width of each image is approximately 1.75 mi.
 

Nevada Geo-Flood Hazard Map in kml

7-20-2010_2-14-51_pm

Two sweet snippets of a new 15mb kml file that shows the distribution of piedmont and playa flood hazards in Ivanpah Valley, Nevada (just south of Vegas) as inferred from geomorphology. I think that the information content of these types of derivative characterizations of hazards is optimized in Google Earth (or similar virtual globe application). In this case, some arguably arcane geological characteristics are boiled down to a straightforward relative hazard scheme running from cool colors (low hazard) to warm colors (high hazard). The closeup is dominated by the 'Barbie' fan (almost too perfect in shape). It straddles the border of NV and CA. Note how the trunk stream just bisects the Lucy Gray Range...Note that the playa at lower left is the proposed site of a major airport. Yes. That is what I said...Airport.

7-20-2010_2-22-06_pm

The other snip is a sky view of the entirety of the map area with Las Vegas just out of the frame at the top. Just look at that playa (Roach Lake...yes...that is right...Roach Lake). Nice and flat. Just begging for an airport. Such ideas are far from outrageous in Nevada. Go check out area 51 sometime.

Using the transparency slider in GE allows for the user to become familiar with the distinctive surface characteristics of Quaternary desert piedmont deposits (mainly alluvial fan deposits) that inform the hazard interpretation. The high-res imagery available for this area really helps in this regard and completely trumps the overall value of a flat, paper, colored map.
 
House, P.K., 2007, Assessment of piedmont and playa flood hazards in the Ivanpah Valley area, Clark County, Nevada. Nevada Bureau of Mines and Geology Map 158, 1:50,000.
 
House, P.K., Ramelli, A.R., and Buck, B.J., 2005, Surficial geologic map of the Ivanpah Valley area, Clark County, Nevada. Nevada Bureau of Mines and Geology Map 156, 1:50,000.
 
Online report coming soon...seriously.

 

 

Google Street-View Roadcut-Geology

I suspect someone has exploited this more fully than I, but recently I was perusing the Google Street View imagery near roadcuts I am familiar with. This one shows a fault in the  Peach Springs Tuff (~18.5 Ma) on I-40 in Kingman, AZ. It is no gigapan, but interesting nonetheless:
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Imagine what could be done with a better camera...taken on a river trip for example. Yikes.

Owyhee River LiDAR drape on low-res Google Earth images

Ok. So Google is apparently never going to upload the high-res NAIP
imagery of the Owyhee River study area. Here is a work-around. Draping
the LiDAR slopeshade image on the bad satellite imagery. Looks pretty damn good! Now we are very
proficient at doing this. On our way to developing some more elaborate
geologic projects in Google Earth. Should probably start with adding the hi-res imagery ourselves....

Thanks to Heather...she made it to the LiDAR class in San Diego last week!

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12-9-2009_2-35-35_pm

12-9-2009_2-34-59_pm

Google Earth is indispensable for geologic mapping.

I've said it before, and I am sure I will say it again. But this time Google Earth is really making a major difference in my approach to making a geologic map.

My mapping project on the Lower Walker River and the piedmont of the Wassuk Range, NV is taxing my skills as a geologist and as a mapper. It is an extremely complicated setting with active tectonics, catastrophic debris flows, rock avalanches, a wildly fluctuating terminal lake, and a river madly scrambling to keep up with the lake's rapid, historical decline (50 m in ~100 years). Documenting the ancient, historical, and recent shorelines along the lake is a key component of developing a fairly tight chronology of alluvial fans, abandoned delta lobes, and Quaternary fault activity. However, efficiently digesting all of this information is a far more laborious task with the 24k USGS base maps because the relief in the area is too extreme to accommodate small contour intervals. Air photos are certainly nice, and I do have access to some marginally good LiDAR data and scattered high-precision GPS points, but nothing brings the area into full focus as easily and as efficiently as Google Earth. On this project I have explicitly incorporated GE into my mapping and it has worked extremely well.

GE allows me to quickly and repeatedly pan and zoom my map area and evaluate all of these features of interest. With particular reference to the logistics of making a geologic map, I have used GE extensively to quickly trace mappable shorelines, tag key elevations, and decide how (or whether) to group them for mapping purposes. I have also marked some of the more flagrant fault traces to improve the frame of reference for the map. Of course, I have also linked my geotagged set of field photos so that I can get some clear reminders about key areas I am mapping. The map is being compiled in ArcGIS with good imagery (NAIP) and I can simply transfer my interpretations by visual inspection. Of course, I keep turning to GE to check things out in detail because, somehow, the clarity of the imagery far exceeds what I can force out of the NAIP. Likely I will turn the map of this intriguing area into a kml project. Best area yet for that.


Posted via email from Fresh Geologic Froth

Google Earth is indispensable for geologic mapping.

9-17-2009_5-35-04_pm

I've said it before, and I am sure I will say it again. But this time Google Earth is really making a major difference in my approach to making a geologic map.

My mapping project on the Lower Walker River and the piedmont of the Wassuk Range, NV is taxing my skills as a geologist and as a mapper. It is an extremely complicated setting with active tectonics, catastrophic debris flows, rock avalanches, a wildly fluctuating terminal lake, and a river madly scrambling to keep up with the lake's rapid, historical decline (50 m in ~100 years). Documenting the ancient, historical, and recent shorelines along the lake is a key component of developing a fairly tight chronology of alluvial fans, abandoned delta lobes, and Quaternary fault activity. However, efficiently digesting all of this information is a far more laborious task with the 24k USGS base maps because the relief in the area is too extreme to accommodate small contour intervals. Air photos are certainly nice, and I do have access to some marginally good LiDAR data and scattered high-precision GPS points, but nothing brings the area into full focus as easily and as efficiently as Google Earth. On this project I have explicitly incorporated GE into my mapping and it has worked extremely well.

GE allows me to quickly and repeatedly pan and zoom my map area and evaluate all of these features of interest. With particular reference to the logistics of making a geologic map, I have used GE extensively to quickly trace mappable shorelines, tag key elevations, and decide how (or whether) to group them for mapping purposes. I have also marked some of the more flagrant fault traces to improve the frame of reference for the map. Of course, I have also linked my geotagged set of field photos so that I can get some clear reminders about key areas I am mapping. The map is being compiled in ArcGIS with good imagery (NAIP) and I can simply transfer my interpretations by visual inspection. Of course, I keep turning to GE to check things out in detail because, somehow, the clarity of the imagery far exceeds what I can force out of the NAIP. Likely I will turn the map of this intriguing area into a kml project. Best area yet for that.