Subsurface storm

Many oxidation reactions require considerable amounts of time to reach equilibrium. In seasonal climates, sufficiently long dry periods may allow stagnant subsurface porewaters to extensively oxidize sulfide grains before flushing from storms. Bacteria also require sufficient time to thoroughly oxidize sulfide surfaces. 

As rainfall decreases, overland flow also decreases, but subsurface runoff continues for several days after the storm as water gradually drains from the soil. This explanation assumes that three water sources of differing chemical characteristics contribute to stream flow, in contrast to the assumption of two water sources made by other authors, for example, Pinder and Jones (45). 

In grade control and drainage applications, considering their sizes and aesthetics, scrap tires are most suitable for small-scale projects on small streams and in small towns and communities. They include overfalls, low water stream crossings, subsurface drainage, storm-water runoff drainage, and roadway cross drainage. 

The initial Sr/ Sr of the sequentially erupted flows on Mt. Falla and on Storm Peak in Fig. 12.34 vary stratigraphically. The first six flows on Mt. Falla actually have a nearly constant initial Sr/ Sr ratio at 170 Ma which has permitted these flows to be dated by the Rb-Sr method in Fig. 12.32. The initial Sr/ Sr ratios of the upper flows on Mt. Falla (7-14) vary systematically between 0.7100 and 0.7121. These variations imply that the magma had a range of Sr/ Sr ratios and that the sequentially erupted lava flows are samples drawn from different parts of the magma in its subsurface reservoir. 

Fig. 3. GC-ECD chromatograms (60 m DB-5 Column) of the PCB fraction from eggs of three fish-eating birds from the Bay of Fundy on the Atlantic coast Leach s Storm Petrel (offshore, surface feeding), Double-Crested Cormorant (nearshore, subsurface feeding) and Atlantic Puffin (offshore, subsurface feeding). Peak identities are as in Fig. 1. Peaks labelled ( ) are unidentified. 

Historical data shall be collected and evaluated on phenomena that have the potential to affect the safety of the research reactor, such as data on volcanism, strong winds, the frequency and severity of lightning strikes, sand storms, severe precipitation, snow, ice, hail and subsurface freezing of subcooled water (frazil). 

Volcanic tremor is a narrowband (usually 1-4 Hz), continuous vibration thought to be due to sustained subsurface movement of magma or volatiles and is often observed before explosive eruptions. It may last from a few minutes to months in duration. Tremor has similar spectral characteristics as low-frequency earthquakes. Harmonic tremor shows one or many regularly spaced overtones in addition to a fundamental frequency. Sometimes spectral peaks in harmonic tremor glide upward (or downward) in frequency over as little as a few minutes. Eruption tremor, a continuous vibration coincident with explosive eruptions, has a wider frequency range (0.5-10 Hz). Dome collapses, lahars, weather storms, and telemetry problems can all produce signals that could be confused with tremor. 

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