high phreatic head
1Aquifer — Typical aquifer cross section An aquifer is a wet underground layer of water bearing permeable rock or unconsolidated materials (gravel, sand, or silt) from which groundwater can be usefully extracted using a water well. The study of water flow… …
2David A. Johnston — David A. Johnston, 13 hours before his death at the 1980 eruption of Mount St. Helens Born …
31980 eruption of Mount St. Helens — Photograph of the eruption column, May 18, 1980 Volcano Mount St. Helens …
4Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
5Chad Basin — The Chad Basin, also known as the Lake Chad Basin, is a large lowland area in north central Africa. In all directions from the center of this area the elevation changes are gentle. The Chad Basin is an endorheic (closed) basin its water does not… …
6Volcanism on Mars — Mariner 9 image of Olympus Mons[1]. This is one of the first images to show that Mars has large volcanoes. Volcanic activity, or volcanism, has played a significant role in the geologic evolution of Mars.[ …
7hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
8Phreatobius cisternarum — Taxobox name = Phreatobius cisternarum status = DD status system = iucn2.3 status ref = [IUCN2006|assessors=World Conservation Monitoring Centre|year=1996|id=40714|title=Phreatobius cisternarum|downloaded=08 Apr 2007] regnum = Animalia phylum =… …
9Geology of the Lassen volcanic area — The geology of the Lassen volcanic area presents a record of sedimentation and volcanic activity in the area in and around Lassen Volcanic National Park in Northern California, U.S.. The park is located in the southernmost part of the Cascade… …
10Mount St. Helens — This article is about the volcano in Washington State. For the 1980 eruption, see 1980 eruption of Mount St. Helens. For the mountain in California, see Mount Saint Helena. Mount St. Helens …
- 1
- 2
