Large Quakes Weaken Fault Zones Worldwide


“The massive 2004 earthquake that triggered killer tsunamis throughout the Indian Ocean appears to have weakened at least a portion of California’s famed San Andreas Fault, according to a new report by U.S. seismologists.

“The findings suggest the Earth’s largest earthquakes can weaken fault zones worldwide and may trigger periods of increased global seismic activity.”

Mapping Natural Population Decreases in the United States


“For an advanced capitalist society, the United States has a quite high birth rate, and substantial natural increase. Yet despite this, almost a third experienced natural decrease, an excess of deaths over births, over the recent 2000-2007 period. Some counties with natural decrease still grow in population because of sufficient in-migration, but more typically, natural decrease is associated with high levels of out-migration and with long term population decline.”

Map Synthesizes Threats to Great Lakes


“Researchers are developing the first regional “threat map” of the Great Lakes. The project, which focuses on the effects of human activity, is designed to help planners and conservation groups in the United States and Canada make decisions and prioritize activities for years to come.

“”Building on previous efforts to map each threat and priority individually, for the first time we now have the ability to generate synthetic maps of threats and their predicted impacts for the entire Great Lakes basin,” says David Allan, professor of aquatic sciences at the University of Michigan and the project’s lead researcher.”

Scientists Join Forces to Explain HIV Spread in Central and East Africa

17080_rel“Scientists studying biology and geography may seem worlds apart, but together they have answered a question that has defied explanation about the spread of the HIV-1 epidemic in Africa.

“Writing in the September issue of AIDS, a research team led by scientists at the University of Florida explained why two subtypes of HIV-1 — the virus that causes acquired immunodeficiency syndrome, or AIDS — held steady at relatively low levels for more than 50 years in west central Africa before erupting as an epidemic in east Africa in the 1970s.”

Quote of the Day

“Perhaps going to the Moon and back in itself isn’t all that important.  But it is a big enough step to give people a new dimension in their thinking–a sort of enlightenment.  After all, the Earth itself is a spacecraft.  It’s an odd kind of spacecraft, since it carries its crew on the outside instead of inside.  But it’s pretty small. . . . From our position on the Earth it is difficult to observe where the Earth is and where it’s going, or what its future course might be.  Hopefully, by getting a little farther away, both in the real sense and the figurative sense, we’ll be able to make some people step back and reconsider their mission in the Universe, to think of themselves as a group of people who constitute the crew of a spaceship going through the Universe.  If you’re going to run a spaceship, you’ve got to be pretty cautious about how you use your resources, how you use your crew, and how you treat your spacecraft.”

–Neil Armstrong

Calculating Forest Land Cover Change in Laos with GIS


Chanhda Hemmavanh and Somchay Inthavong.

Presented at the 36th Natural Areas Conference, “Living on the Edge: Why Natural Areas Matter”, Vancouver, Washington, USA, September 15-18, 2009.

Land Use Changes were traced during 10 years from 1992 to 2002 in Phongsaly National Biodiversity Conservation Area (NBCA), one of the most important NBCA and rich in biodiversity in Lao PDR, based on satellite image interpretation and field verification in order to identify causes of the changes. The dynamic information of the forest land cover change during 10 years was calculated by the map algebra in ArcGIS 9.2. Based on the theory of ecosystem service function and the service function value of global different ecosystem services values (ESV) provided by Costanza et al, the value of the six forest cover and land use categories in the Study Areas was worked out. Ecological environment effect that the regional land cover change produced in study period was calculated. A principal component analysis (PCA) was used to quantitatively study driving forces of forest land use change. Results showed that forest land cover declined 15463.35 ha about 12.39% from 1992 to 2002, resulted that in a $31050406.80 net decline in ecosystem services of forest category respectively. The economic and population factors were the principal driving forces of forest cover change in the study area. ESV, PCA were a suitable method for investigating driving forces of forest land cover change and finally policy concerning to biodiversity and sustainable use of the natural resources were developed.

Map of the Day: Beydagi Forest Map

…from the ESRI Map Book, Volume 24


“This is a forest stand-type map produced for one of the 1,308 subdistricts of Turkey’s forest management plan. These plans are renewed every ten years. Aerial photos are combined with the field work to create final forest maps. The database structure, standards, and symbols are developed for Turkey.

“Courtesy of Umut Adigüzel, General Directorate of Forestry.”