Category Archives: Web Resources

Smithsonian geological timeline

A measure of the quality of a science website, apart from its visual appeal, is a mixture of how much it teaches you and what you can snaffle to help teach others. As a point of departure for E-geology, it will be hard to beat the Smithsonian Institutions geotime site (www.nmnh.si.edu/paleo/geotime). That’s because it focuses first on the history, and if you care to you can discover how that was constructed from the geological record. Its central organiser is a slider that can be zoomed, which lays out the geological past – the literal time line divided into stratigraphic Eons, Eras, Periods and Epochs. Each division is clickable, although zooming in several times is needed to see the Cenozoic Epochs. But, hang on, there is no Ediacaran Period, the newest addition, nor the subdivision of the Proterozoic on the timeline. Whatever, clicking on a division opens a thumbnail sketch of each and links to pages that give more detail on the highlights, plus introductions to the founding concepts behind geological time and unravelling Earth and life processes. There is a glossary, which shows the influence of Encarta and Wikipedia. Here is a chance to learn for hours in a most convenient and engaging way, but graphics are few and far between in the various main panes. There are examples of important fossil organisms, but displayed at a size that lacks satisfying detail. What the site needs are maps and explanatory diagrams, which are available elesewhere. So the Smithsonian needs, I think, to liase a bit with other learning resources in the geosciences. It would be good to have a one-stop shop.

Here is the earthquake forecast

Earth Pages News of June 2005 reported on the development by the US Geological Survey of the first daily seismic forecasting service, which covers California.  It has a web site at http://pasadena.wr.usgs.gov/step.   The forecast is for events, generally aftershocks of earlier earthquakes, with sufficient energy to throw objects off shelves (Modified Mercalli Index VI). On June 30 2005, Lake Tahoe had a chance around 1 in 100 of such a tremblor, with the length of the San Andreas and related fault systems highlighted at between 1 in 10 000 to 1000.  Of course, it will take some time before people link as quickly as they do to the weather forecast.

Tree-ring heaven

Growth rings in tree trunks are among the best records of local climate variation that there are: they provide an annual “stratigraphy”.  So intricate are the records that it has proved possible to match ring sequences in ancient but still growing trees to those found in logs of even greater antiquity, thereby building up a “dendrochronology” that extends back into history.  Tree rings help historians link human affairs to a background of changing conditions for life.  Henri Grissino-Mayer of the University of Tennessee has brought together a wealth of dendrochronological information in his Ultimate Tree Ring Pages at web.utk.edu/%7Egrissino/default.html.

Cyber-tourism

There are so many places one might wish to visit for their scenery and physical geography, yet only limited resources and, of course, time.  The availability of high-resolution satellite images, together with free data that show variations in topographic elevation newly released from the Shuttle Radar Topography Mission, enables realistic simulations of just about anywhere.  William Bowen of the California State University has exploited this opportunity to give all-comers a view of most parts of the land surface, as if they were looking obliquely downwards from a high-altitude aircraft – geogdata.csun.edu/world_atlas/index.html

Mineral wealth

Although there are many glossy books about museum quality mineral specimens, as well as being expensive they often only cover a selection of those minerals known to science.  One of the beauties of the web is that a site can cram in as many pictures and ancillary data as its server permits, and anyone can browse what is on offer.  One such site has been set up by consulting geologist David Barthelmy, which not only illustrates more than 2000 different minerals (half the site’s content of 4300) but allows users to examine their molecular structure interactively – webmineral.com

Wanna see an earthquake?

Most of us have grown used to thinking that earthquakes have an epicentre at some fixed point beneath the surface. That is not at all true, as the event that set the Boxing Day 2004 tsunamis in motion as been shown to have been a lengthy rip that propagated from Sumatra NNE to the Nicobar Islands, over a period of about an hour.  Even quite small earthquakes are distributed and often migrate along a fault line.  Christine arson of the University of Colorado has captured what is effectively a movie of a magnitude 8.3 event off the island of Hokkaido, Japan, which can be viewed at spot.colorado.edu/~kristine/tokachi_rupture.gif. The data that she used comes from a network of  a thousand highly sensitive GPS receivers set up throughout Japan.  Instead of acceleration, measured by conventional seismometers, GPS records actual position in x, y, z coordinates.  That enable the actual motions to be imaged as in  the movie.

An electronic antidote to eclecticism

It is a plain to me as to any reader that EPN  is eclectic, and in some cases pretty impressionist; how else to write a monthly weblog about the broad spectrum of geoscientific developments?  So it is good to see websites with a much narrower focus, yet that manage to inform entertainingly and provocatively.  Such a site is www.mantleplumes.org, organised by Gillian Foulger of Durham University, currently a visiting scientist with the Volcano Hazards Team at USGS, Menlo Park, USA.  It covers the whole of “plumeology”; the tectonics, the magmatism, ages and wider features, even ideas about the presence or absence of plume-related features on other planets.  It has some powerful contributing essayists, such as Don Anderson and Warren Hamilton, who are not averse to scepticism and critiques, and represent work in progress on a book, Plates, Plumes & Paradigms just submitted to the Geological Society of America – a rare event to see preprints of book chapters.  It serves an educational role as well, with well-illustrated and up-to-date reviews of the mechanisms involved in large-igneous provinces., and thumbnails on a continent-by continent basis. Jason Morgan came up with the “hot-spot” idea about 33 years ago and launched a revolutionising force in plate tectonics.  It is good to see that there is still a vibrancy about the topic.

Ancient art

The hallmark of modern human’s abilities is the art left behind by our ancestors since about 30-40 thousand years ago.  Among the most enigmatic are those by Australian native people, that might date back as far as 50 ka.  The first were discovered by Joseph Bradshaw and his brother in the Kimberly Ranges of northern Western Australia in 1891.  The Geneva-based Bradshaw Foundation (http://www.bradshawfoundation.com/) is developing a comprehensive archive of rock-art images from across the globe, which will uplift anyone who visits it.

Three web sites that have been suggested are well worth browsing.  Bernie Gunn has assembled a monumental database of the geochemistry of volcanic rocks at http://www.geokem.com .  That, in itself,  is a magnificent resource for anyone working on the topic, but the site also has a comprehensive guide to good laboratory practice that will be invaluable to anyone beginning to work in the field., plus a host of good reference material and links.  Its quality is hardly surprising since Bernie has been engaged in geochemical research for more than 3 decades at the University of Montreal.  Another dimension to geological web resources is revealed by that compiled by Fettes College in Edinburgh at http://www.fettes.com/shetland .  It is an encyclopaedic source of environmental information on one of Britain’s many microcosms of Earth science.  It ranges from the Shetland Isles’ long geological evolution to its present geomorphology.  Fettes is a private school, with a glittering roll of alumni.  Equally encyclopaedic is http://paleodb.org , which is as near to a global database of palaeontology as you can get at present.  One of the highlights is being able to plot occurrences at the genus and species level on interactive maps, as well as browse and analyse the contents statistically.  Users do need to know how to spell taxonomic names!  Once you have compiled a map (the only trilobite whose name I can spell is Dalmanites!), you can zoom in.  If you click on an occurrence up comes a summary of the locality, with links to other parts of the database, including other fossils at the locality.  Wisely, location detail is crude enough to deter collectors from ravaging sites.  The database is compiled by 140 contributors in 11 countries.  This a site for specialists, but a beginner can learn a great deal from it.

Mineralogy links

Information on mineralogy is often hard to find on the web, so the University of Wurzburg Institute of Mineralogy in Germany has created a comprehensive set of links that cover a wealth of topics.  They include teaching materials at different levels, information on experimental and analytical techniques, thermobarometry, mineral descriptions and crystallography, economic mineralogy, gemmology and much more besides.  Go to http://www.uni-wuerzburg.de/mineralogie/links.html

Human origins site – the palaeoanthro weblog

This seems to be a blog well worth examining and mining – www.talkorigins.org/faqs/homs .  The blogger, Jim Foley, maintains an excellent sense of humour as well as what appears to be considerable energy and knowledge.  There is a link to a masterful April Fool’s Day joke at the expense of the Institute for Creation Research, which gulled their radio show, Science, Scripture and Salvation in 2000 into accepting at face value a spoof article in the April 1997 issue of Discover magazine.  This was penned by the German palaeoanthropologist Oscar Todkopf (Deadheads are fans of the Grateful Dead) of Hindenburg University (Led Zeppelin and a well-known, flaming bag of gas), which documented a find of assorted musical instruments, (a 6 foot length of mammoth tusk turned into a tuba, a bagpipe-like instrument made from the bladder of a large animal, a triangle of thin bones, a collection of hollowed out bones of different lengths, which Todkopf suggested might be part of a xylophone (he called it a ‘xylobone’), the first known Neanderthal cave painting, showing marching musicians alongside some suspected musical notation, and a Neanderthal skull) in the famous Neander Valley, Germany. Even the fact that the eponymous author claimed that Neanderthal musicians played the bagpipes with their remarkably huge noses, did not deter the ICR’s Marvin Lubenow, author of the leading creationist book on human origins, Bones of Contention, from commenting, “There’s overwhelming evidence that Neanderthals were musically inclined.”, along with a further stream of howlers.  For that alone, you must visit this site.  However, it is probably the best source of human-origins information, illustrations and news that there is on the Web, and puts the EPN anthropology and geoarchaeology section to shame!  There is a balance, for the site includes a great many items on creationist ideas, but this has to be tongue in cheek, despite the accuracy of the accounts there. I wonder who Jim Foley is….

Impacts’ effects

Algorithms that model the physical effects of extraterrestrial impacts from the Lunar and Planetary Laboratory of the University of Arizona, headed by Jay Melosh, have been assembled into a handy on-line calculator, with notes on the processes involved.  If you want to find out if you will be fried, buried or blown to smithereens (probably all three if our luck is really out), and the chances of being harmed by alien lumps of rock or ice, you can find the calculator at http://www.lpl.arizona.edu/impacteffects/ .  It is not recommended for estate agents, because, unlike many other disastrous events, impacts can be anticipated anywhere.