net gas thickness
31Spirit River Formation — Stratigraphic range: middle Albian …
32Horn River Formation — Stratigraphic range: Middle to Late Devonian …
33Snowball Earth — The Snowball Earth hypothesis as it was originally proposedcite book author = Kirschvink, J.L. year = 1992 chapter = Late Proterozoic low latitude global glaciation: The snowball Earth title = The Proterozoic Biosphere: A Multidisciplinary Study… …
34Europa (moon) — Europa Europa s trailing hemisphere in approximate natural color. The prominent crater in the lower right is Pwyll and the darker regions are areas where Europa s primarily water ice surface has a higher mineral content. Imaged on September 7,… …
35Ice core — An ice core is a core sample from the accumulation of snow and ice over many years that have re crystallized and have trapped air bubbles from previous time periods. The composition of these ice cores, especially the presence of hydrogen and… …
36Effects of global warming — This article is about (primarily) effects during the 21st century. For longer term effects, see Long term effects of global warming. The variou …
37hydrosphere — /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… …
38Ishbel Group — Stratigraphic range: Permian …
39Arctic Regions — ▪ 2009 The Arctic regions may be defined in physical terms (astronomical [north of the Arctic Circle, latitude 66° 30′ N], climatic [above the 10 °C (50 °F) July isotherm], or vegetational [above the northern limit of the tree line]) or in human… …
40Cluster (spacecraft) — Cluster Operator European Space Agency in international collaboration with NASA Major contractors Dornier GmbH (now part of EADS) Mission type Orbiter Satellite of Earth …
