The claim by Furnes et al. (Reports, 23 March 2007, p. 1704) that Greenland metavolcanic rocks require Paleoarchean sea-floor spreading is incompatible with their own data. The purported sheeted dikes have the composition of pyroxenitic komatiite and could not have fed the adjacent ferroandesitic pillow lavas. Neither type has ophiolitic analogs, and both are likely ensialic.

Orientation of the eruption fissures and composition of the lavas of the Miyakejima volcano is indicative of the competitive processes of the regional tectonic stress and the local stress generated by the activity of a magma plumbing system beneath the volcano. We examined the distributions and magmatic compositions of 23 fissures that formed within the last 2800 years, based on a field survey ...

Spur dike is a common hydraulic structure, which is widely used in hydraulic engineering such as channel regulation, flood prevention and river diversion for preserving the desired water depth, deflecting the main current and protecting river banks. In actual operations, spur dikes exert influence on river system usually in the form of groups, and the flow field around spur dike group is compli...

Recent estimates of the magnitude and orientation of lithospheric stresses are reviewed. Data come from a variety of sources including earthquake focal mechanisms, fault slip data, young volcanic dikes and feeders, in-situ stress measurements at depth, lithospheric flexure models, microstructure paleopiezometry, and consideration of constraints on maximum stress differences from laboratory-dete...

Statistical dependence among random hydraulic variables generally stem from a common meteorological cause. Usually, this dependence increases the probability of occurrence of floods. Therefore, in many (potential) applications in flood risk analysis there is a need for techniques that properly describe the statistical dependence among random variables. This study makes an inventory of existing ...

The crest level of coastal structures such as dikes and breakwaters is often based on estimates the amount wave overtopping. One important parameters affecting overtopping angle incident waves since oblique can significantly reduce compared to perpendicular attack. Based 3D physical model tests dikes, rubble mound vertical caisson breakwaters, influence attack has been evaluated. A new expressi...