Definition of a Plume. Stress- and dike-based models recognize that the difference between a surface volcano (âhotspotâ) and sills, intrusion, magma chambers and underplating is simply one of the orientation of the stress field, not the absolute temperature of the mantle, or even the magnitude of the stress.
Hempstead is a city in Waller County, Texas, United States, part of the HoustonâThe WoodlandsâSugar Land metropolitan area. It is the county seat of Waller County.
Hemel Hempstead. Hemel Hempstead, town and urban area (from 2011 built-up area), Dacorum district, administrative and historic county of Hertfordshire, south-central England, northwest of London. The first charter was granted in 1539.