A comparison of rift-zone tectonics in Iceland and Hawaii

Observed observations of eroded volcanic lift zones indicate that Icelandic dams are typically several times thicker than Hawaiian dams. However, geodetic and seismic observations of active ruptures indicate that the embankments in the two regions are very similar. If the lift zone has the same elasticity, this means that the Icelandic embankment has higher propulsion pressure than Hawaii (magma pressure minus the compressive stress perpendicular to the embankment plane). The second major difference between the two regions is the high prevalence of large normal faults in Iceland's Lift Valley. I can guess that the proportion of Icelandic dams is lower than the proportion of Hawaiian dams. Therefore, the Icelandic embankment is affected by higher propulsive pressure, but absolute magma pressure is lower than Hawaii. These differences can be explained by the structural background of the two regions. In Iceland, stable long-range stretching reduces the horizontal stress perpendicular to the lift zone, allowing the dam to enter at low absolute pressure, but when magma is available, the driving pressure is high. In Hawaii, a more continuous supply of magma on the time scale of stress relaxation induced by embankment, and in the penetration of long-term tear extension that ensures that crack-compressive stress does not significantly alleviate the embankment before It may play a greater role. Therefore, magma pressure must be sufficient for the eruption to cause intrusion. If the crack relaxation mechanism is not so efficient, a higher percentage of dams will be jetted, and sometimes the trend of the lift zone may be undesirable due to dike intrusions. This may be the case of Mauna Loa, it lacks large crack defects and cracks, and has many radial vents on the outside of its two major tear belts.

In order to show another uncertainty, mafic rocks formed apart from the ridge mimic structurally interrupted ophiolites. The lift zone of major buildings like Hawaii is a serious problem. Cracks spread several centimeters a year. In the ocean floor section, a pillow basalt covers the dam and then covers the gabbro (eg Okubo et al., 1997). It is even more difficult to distinguish sea parrot and diving pillow with deformed deformed outcrops. Locally, the area of ​​the side of the building is similar to the front thrust fault (eg Morgan et al., 2003).

Observed observations of eroded volcanic lift zones indicate that Icelandic dams are typically several times thicker than Hawaiian dams. However, geodetic and seismic observations of active ruptures indicate that the embankments in the two regions are very similar. If the lift zone has the same elasticity, this means that the Icelandic embankment has higher propulsion pressure than Hawaii (magma pressure minus the compressive stress perpendicular to the embankment plane). The second major difference between the two regions is the high prevalence of large normal faults in Iceland's Lift Valley. I can guess that the proportion of Icelandic dams is lower than the proportion of Hawaiian dams. Therefore, the Icelandic embankment is affected by higher propulsive pressure, but absolute magma pressure is lower than Hawaii. These differences can be explained by the structural background of the two regions.