Wednesday, October 12, 2011

It's Earth Science Week - Day 4 - Park Photos

Properly labeled geophotos can offer an interesting and useful teaching tools. In some cases, I have managed to convince friends to provide travel photos to cover areas not yet visited. [More meaningful commentary will be added later.]

Tuesday, October 11, 2011

Day 3 - It's Earth Science Week - Badlands and Hoodoos

Just a few interesting landforms - large, medium, and small - courtesy of Mother Nature.

[Explanations and notes, later.]

Monday, October 10, 2011

Day 2 - It's Earth Science Week - Columnar Jointing in Basalt

Will try to post each day of this week.

A fellow Geologist on Facebook posted the "what if" you could make pavers from columnar-jointed basalt. I posted these images on FB, so as to give casual readers an idea of what we were discussing - in some jest. The conclusion was (on my part) that basalt pavers would be neat, but because of access problems and logistics, it probably wouldn't work. The first 3 photos were from park areas, while the fourth is in a Wilderness Study area, 1 mile plus from any parking - even if it was legal.

This particular photo from Yellowstone was a scanned slide, taken by my Dad in the summer of 1980, while he and my Mom were on their last vacation together.  He passed away that November.

A good friend went on a short vacation with his dad, brother, and son and got a number of photos of Devil's Tower in Wyoming. 

The Aden Basalts - flood basalts from fissure eruptions - are located in southern Doña Ana County, New Mexico.

For those not familiar with columnar basalts, they usually form vertical, elongate polygons with 5 - 7 sides, during the cooling of surface and near-surface basalts in flows and volcano necks as you can see here. I seem to remember there being some columnar joints in some parts of the Palisades of the Hudson sill, but don't have any photos.

Sunday, October 9, 2011

Day 1 - It's Earth Science Week - What Can You Do?

One of the best ways to celebrate Earth Science Week (Oct. 9-15), is to show some appreciation to Earth Scientists.

 Here are some ideas:
  • Take an Earth Scientist to lunch.
  • Be patient with our eccentric ways.
  • Understand that just because we may not have books on sale at Barnes & Noble, that doesn't mean that we aren't writers. We are sujbect to "writer's block" and when the "dam bursts", we may need to write down our thoughts before we lose them.
  • Be empathetic with us - as during decades of travel with others - we pass thousands of rock outcrops and other sites of interest, without stopping.
  • Just because we talk to ourselves, we are not necessarily crazy, we may be rehearsing a lecture or an explanation of a particular scientific issue.
  • It is OK if we say "I don't know".  It doesn't mean we are not looking for an answer.
  • Part of being a scientist is observing things and seeking an explanation.  Don't be surprised if we take an interest in things outside of our particular discipline.
  • Many of us have a never-ending "yearning to learn", so please don't be offended (or surprised) if we bring a textbook or small reference book with us during a casual lunch.  We may be trying to reach a "learning plateau" on a particular subject, in case the opportunity arises to offer an educated opinion.
Other things may be added, as they come-to-mind.

Friday, October 7, 2011

Gold Fever Flows On

From each one of the sluice videos, you can get some ideas, if you are interested in building your own.

Turbopan, hmmm.

A test of a highbanker, designed to speed up the removal of larger gravel.

Gold Grabber, another good idea.

More Low-Grade Gold Fever

I have never owned or used a sluice box, but I am getting a "hankering" to build one. As a reminder, you have to remember to check on the status of the stream, so as not to get hammered for violations of regulations.

Also as I said previously, it is best to try to avoid excessive environmental damage. Try to restrict your digging to the active channel and eroded material along the margins (if old creek gravels are being eroded).

Still Nursing a Low-Grade Gold Fever

Panning with Jayda, not your stereotypical gold miner. You can see in the early part of the video that this is not a casual operation. And as I am "environmentally aware", I am concerned about excessive disruption of streams - by digging into the banks. Digging in the channel itself (and in the eroded material from the banks) is not much different that what nature would do during a heavy storm.

But this appears to be the floor of an old mine, the environmental damage has already been done. Or maybe it is an active mine.

She knows what she is doing, I wish her luck in her endeavors. (I wonder where she is?)

Wednesday, October 5, 2011

What Was the Pleistocene? [Original Post Date: 10/25/05]

Before we get to the issue of the Pleistocene re-wilding of North America, some may be wondering "just what exactly does "Pleistocene" mean?

"Pleistocene" refers to a specific interval of geologic time that is estimated to have lasted from 1.8 million years ago to 10 thousand years ago. It is best remembered as being the time of the last major Ice Age. Many scientists believe that "today's" warm climate is simply a natural rebound (or recovery) from the last Ice Age.

Referring to the accepted Geologic Time Scale (different versions may have slightly different age estimates), geologic time is divided into a hierarchy of time periods, based on different criteria. Most of the time boundaries are based on significant changes in the sedimentary rock and fossil record, as observed in 18th and 19th century Europe, where most of the present Geologic Time Scale was devised and defined. All of the time units, within the various categories, are of differing lengths.

The broadest time periods (at the top of the hierarchy) are "Eons", which cover hundreds of millions of years. We live in the Phanerozoic Eon, which began approximately 544 million years ago with the first widespread appearance of hard-shelled marine organisms.

Eons are divided into "Eras", which cover tens of millions of years. We live in the Cenozoic Era, which began approximately 66 million years ago with the end of the Mesozoic Era, when the dinosaurs became extinct.

Eras are divided into "Periods", which cover millions to tens of millions of years. The Cenozoic Era consists of the Tertiary Period (66 million years ago to 1.8 million years ago) and the Quaternary Period (1.8 million years ago to the present).

Periods are divided into "Epochs", which cover hundreds of thousands of years to millions of years. The Quaternary Period consists of the Pleistocene Epoch (1.8 million to 10 thousand years ago) and the Holocene (or Recent) Epoch (10 thousand years ago to present). The dividing "line" between the two epochs is the last major ice age.

As details of the geologic record become less distinct as we go back in time, the Epoch time classification is only used on a world-wide basis for the Cenozoic Era, i.e., the last 66 million years.

With the mass extinction at the end of the Mesozoic Era (and the end of the Cretaceous Period, too), approximately 66 million years ago, the niches and habitats of the world's ecosystems were "emptied out" of dinosaurs and other organisms. The mammal and bird survivors refilled these vacant niches and habitats with an "Adaptive Radiation", i.e., whereas the previous Mesozoic Era is known as the "Age of Reptiles", the Cenozoic Era is known as the "Age of Mammals".

With the natural global warming that ended the last Ice Age, human populations rapidly grew, cultures developed and humans migrated, in our case, most notably from Asia into North America. There was a significant extinction of large Pleistocene mammals in North America, attributed to human activities by some scientists, while others consider other possible causes (but not excluding the "human effect").

The article linked at the top of this post addresses the plans to introduce large African and Asian mammals (megafauna) to North America, to "replace" that which was lost in the last 10,000 years or so.

A Report on the State of the Geoblogosphere...

is discussed on the German blog Geonetzwerk which presents;

..."data from an online survey with 78 participants and from analysis of more than 200 Earth science blogs.

Our survey shows that a majority of persons writing geoblogs are young, male, and academic. Most live in the USA and Europe. Collectively, their main motivation to blog is to share knowledge and to popularize the geosciences. Blogging is also seen as an opportunity to improve the authors’ writing skills, perform outreach, establish new contacts, and positively influence their careers. The rapid dissemination of news has been cited as an important advantage of the geoblogosphere."...

A little history:

..."The first geoscientific blogs were released in 2001 with “Green Gabbro” (Bentley, 2008) and in 2003 with “Andrew’s Geology Blog”. Building on the term “blogosphere”, blogging geoscientists soon established “geoblogosphere” as shorthand for the entirety of the geoblog community, including bloggers and readers.

In January 2010 the “Geoblogosphere News” aggregator by Huber et al. (2009) had tallied 265 blogs dealing with Earth sciences. This represents an increase in the size of the geoblogosphere of more than 100 % compared to the previous year."...

For what it is worth, my original blogging began in February 2005, though it was a hodgepodge of science, politics, culture, etc., so for that reason, it probably doesn't fit with the proper geoblog definitions of some.

There are some concerns - as there would usually be with a wide-open free-for-all atmosphere. Freedom can be messy.

..."Serious concerns about the credibility and trustworthiness of science blogs have been raised (Ashlin & Ladle, 2006). But no systematic approach to characterize the geoblogosphere has been carried out yet. Similarly, the geoblogging phenomenon has been incompletely documented. What is the geobloggers’ motivation to write? What is their background, both societally and scientifically? What are their information sources? How do they assess the benefits and disadvantages of blogging? What role will geoblogging play for the future working of the Earth sciences?

The first data on geoblogs were collected by Bentley (2008) who conducted a short online survey with 46 participants representing approximately 50 % of the geoblogosphere at that time (Geißler, 2009). Another geoblog-survey was started in August 2009 (female participants: n = 91) to investigate geoblogs as a resource and social support network for women geoscientists (Hannula et al., 2009a, 2009b; Jefferson et al., 2010). This survey included bloggers (n = 36) and blog readers.

With the rapid development of geoblogging, the authors extended and reissued the survey of Bentley (2008), supplemented by data from statistical and semantic analysis of more than 200 Earth science blogs. The study presented here is the first comprehensive attempt to characterize the geoblogosphere from the bloggers’ point of view."

Some other considerations:

..."Blogs have potential to be used as educational tools. In the past several years, several studies have shown that blogs support collaborative, participative learning (Agostini et al., 2009; Hall and Davison, 2007), increase student and teacher relationships, improve flexibility in teaching and learning (Ferdig and Trammell, 2004), and teach students the art of scientific argument (Moore, 2008). In the geosciences specifically, blogs can be powerful instruments to visualize geological phenomena, present annotated field trip guides, or accompany geo-educational projects like “Earth Learning Idea”, which supports teachers and teacher-trainers with Earth-related teaching ideas (King et al., 2008a, 2008b).

The fact that more than 78 % of the surveyed geobloggers write their blogs to acquaint laymen with geosciences suggests that geobloggers see blogging as being a form of geoscientific outreach work. One geoblogger wrote: “The whole goal of being a research scientist is to get your research out as quickly as possible to the widest possible audience. A well-known blog lets you do that very effectively. Our ideas reach people that they would never reach if they were only in our formal publications, and also act as a “gateway drug” to get people onto those publications where the ideas are worked out with full rigor.” Wilkins (2008) reached a similar conclusion; he argued that blogging should be understood as fundamentally outreach for science.

Meanwhile, public geoscientific institutions and societies focus more and more on blogging to increase their visibility to other geoscientists and to a wider public (e.g., AGU, 2010). This includes, for instance, blogs maintained by geological surveys, blogs about research expeditions, and conference blogs. The latter issue has been discussed by Bradley (2009) with the result that he evaluates conference blogs as more advantageous than not."...

Not as much as I should, I sometimes use this blog and my college blog as a teaching tool. I usually leave this blog for the more in-depth discussions or for things not discussed in class.

[For the sake of brevity, you should visit the original linked post for the "rest of the story. For what it is worth, I don't recall if I participated in the original survey or not. At that time, I had not "spun off" this (largely) non-political geoblog, so the politics of the original may have put some people off. We are what we are...]