Geology topics

Research about East Molokai Volcano

Source-linked reports with geographic coverage including East Molokai Volcano.

2 recordsLinked to original sources

USGS1995

Evaluation of ground-water resources From available data, 1992, East Molokai Volcano, Hawaii

Available ground-water data for East Molokai Volcano consist of well-construction information and records of ground-water pumpage, water levels, and chloride concentrations. Ground-water pumpage records are available for ten wells. Seventeen long-term (10 years or more) records of water-level and/or chloride concentration are available for eleven wells; however, only seven of these records are for observation wells. None of the available data show significant long-term changes in water level or chloride concentration; however, short-term changes due to variations in the quantity of water pumped, and rainfall are evident. Evaluation of the historical distribution and rates of ground-water pumpage, and variations in water levels and chloride concentrations is constrained by the scanty distribution of spatial and temporal data. Data show a range in water levels from greater than 850 feet above mean sea level in wells located in the windward valley of Waikolu to about 10 feet in wells located east of Kualapuu to 1 to 5 feet in the wells located along the south shore of East Molokai Volcano. An accurate contour map of water levels and chloride concentrations at the surface of the basal-water body cannot be constructed for any time period. Because water-level and chloride data are not collected at regular time intervals, many long-term records are incomplete. Information on the variation in chloride concentration with depth through the freshwater part of the basal-water body and into the zone of transition between freshwater and saltwater does not exist.

Hawaii↗

USGS1973

Petrology, mineralogy and geochemistry of the lava of East Molokai Volcano, Hawaii

The island of Molokai, a volcanic doublet, is the fifth in size of the islands of the Hawaiian Archipelago, which extends about 2500 km (1554 mi) southeastward across the central Pacific Ocean from Kure on the northwest to Hawaii on the southeast (Fig. 1). The broadly linear chain of islands which make up the archipelago caps the Hawaiian Ridge, a pronounced topographic high on the Hawaiian Swell. The ridge is bordered by the Hawaiian Moat (or Deep) which is in turn bordered by the Hawaiian Arch (or Rise). These three topographic features, the ridge, moat and arch, are superposed on a broad elongate ridge, the Hawaiian Swell (Betz and Hess, 1942; Dietz and Menard, 1953). Dana (1849, 1890) recognized from geomorphic evidence that extinction of the chain progressed from northwest to southeast, and McDougall (1964) confirmed the general progression with K-Ar ages of lavas from Kauai, Oahu, Molokai, Maui and Hawaii. The general progression of ages of the Hawaiian-Emperor chain and its relation to Cenozoic Circumpacific tectonics has been described by Jackson et al. (1972) and Dalrymple et al. (1973). Fiske and Jackson (1972) have investigated the influence of regional structure and local gravitational stresses on the orientation and growth of Hawaiian volcanic rifts. Macdonald and Abbott (1970) give an excellent summary of the geomorphology of the Hawaiian Islands and of the processes that formed, and are continuing to form them. This summary contains a geologic sketch of each of the major windward islands (extending from Kauai to Hawaii) individually, and the leeward islands (extending from Kure to Nihoa) as a group.

Hawaii↗