On Thursday October 2, 2014 the membership in the Speleogenesis Network has reached 1000 ! The lucky registration was by Jim Goodbar of US, - welcome, and congratulations!
Cecilio López-Tercero, profesional speleologist was injured during the exploration of the karst system in Leymebamba, Amazonas, located in the Andean Cordillera.
The session on evaporite karst will be held at the South-Central Section, Geological Society of America (GSA) meeting in Stillwater, OK, on March 19-20, 2015.
The State of Minnesota has positions open for hydrologists. These positions include some for hydrogeologists.
Mine Water Solutions is a conference focused on EXTREMES and SOLUTIONS to mine water issues in very challenging environments. It will be held in Vancouver, Canada, April 12-15, 2015.
Did you know?
That natural arch is 1. a residual portion of the roof of a subsurface karst cavity which has not collapsed. such a natural arch may occur as a surface topographic feature, or as a part of a cave system . 2. a rock arch or very short natural tunnel; contrasted with natural bridge, which spans a ravine or valley . synonyms: (french.) arche naturelle; (german.) naturlisches gewolbe, naturbrucke, felsfenster, felsbrucke; (greek.) physike apsitha; (italian.) arco naturale; (russian.) estestvennaya arka; (spanish.) arco natural; (turkish.) dogal kemer; (yugoslavian.) prirodni svod, luk, naravni obok. see also natural bridge.?
Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms
Featured article from geoscience journal
This study demonstrates the significant influences of the geological structure (especially folding and lithology) and the karst system on groundwater flow regime. Folds divert groundwater flow from the general hydraulic gradient; marly layers sustain several perched sub-aquifers above the regional aquifer; and karstification increases the hydraulic conductivity by several orders of magnitude. These phenomena are quantitatively demonstrated within the Yarqon-Taninim (YT) basin, Israel, which is a complex groundwater system, combining several (extremely) opposite characteristics: humid and arid recharge zones, phreatic and confined parts, shallow and deep sub-aquifers, stratified and relatively-homogeneous sub-basins, saline and fresh water bodies, as well as stagnant and fast-flowing groundwater regions.
We have introduced a 3D geological-based grid for the basin (for the first time). It was implemented into a numerical code (FEFLOW), which was used thereafter to analyze quantitatively the flow regime, the groundwater mass balance, and the aquifer hydraulic properties. We present up to date conceptual understanding and numerical modeling of the YT flow field, especially at its mountainous parts.
Based on the calibration procedure and the sensitivity analyses, we obtained the best-fitted hydraulic conductivity values for the aquifer mesh. The general phenomenon observed is that as groundwater flow quantity increases, the hydraulic conductivity also increases. We interpret this result by the karstification mechanism (including paleo-karst). Thus, where groundwater flow-lines converge and where groundwater discharge amount increases, the karstification process intensifies and permeability increases. Consequently, at the mountainous region, along the syncline axes, where groundwater flow-lines converge, higher conductivities are found.
Modeling results also exhibit that at the lowland confined area, the geological structure does not play a major role in directing groundwater flow. Rather, the flow field is controlled by the well-developed karst system and the relatively homogenous carbonate section. It is hypothesizes that the extensive karstification took place at the Messinian Salinity Crises, 5.5 Ma, during which groundwater heads as well as sea level were lowered by several 100 m.