ML of the 1989 Loma Prieta earthquake

The use of regional attenuation in computing the local magnitude, M_L, from strong motion data gathered at distances less than 100 km may lead to systematic underestimates approaching 0·5 magnitude units (Trifunac & Herak, Soil Dynamics and Earthquake Engineering, 1992, 18, 229-41). The use of the attenuation law Att(Δ), for example, with synthetic estimates of Wood-Anderson seismometer response, during the Loma Preita earthquake, leads to estimates of M_L which agree with the surface wave and moment magnitudes, and which are essentially distance-independent.     

The magmatic evolution of the Seiland province,and Caledonian plate boundaries in northern Norway

The synorogenic intrusive activity of the eastern part of the Seiland province evolved from tholeiitic basalt low in K and Ti, through high-K calc-alkaline magmas and possible transitional basalt, to alkaline olivine basalt and picrite; finally, highly differentiated alkaline magmas and carbonatites were emplaced. For intrusive rocks with equivalent SiO₂ contents, K₂O, K₂O + Na₂O and K₂O/Na₂O increased with time, and the degree of iron enrichment in basaltic suites dimished. The western part of the province shows no equivalent evolution, tholeiitic magmas being emplaced at the same time as calc-alkaline magmas to the east.The magmatism is believed to have stemmed from a diapiric complex established in the mantle above a Benioff zone dipping to the east beneath the deforming Andean-type margin of the Baltic plate. Tectonic shortening of the continental edge and rearward movement of the underthrust plate relative to the asthenosphere resulted in migration of the plate junction, steepening of the seismic zone, and increasing depth to the magmagenetic region.     

STEREO SECCHI and S/WAVES Observations of Spacecraft Debris Caused by Micron-Size Interplanetary Dust Impacts

Early in the STEREO mission observers noted that the white-light instruments of the SECCHI suite were detecting significantly more spacecraft-related “debris” than any previously flown coronagraphic instruments. Comparison of SECCHI “debris storms” with S/WAVES indicates that almost all are coincident with the most intense transient emissions observed by the radio and plasma waves instrument. We believe the debris is endogenous (i.e., from the spacecraft thermal blanketing), and the storms appear to be caused by impacts of large interplanetary dust grains that are detected by S/WAVES. Here we report the observations, compare them to interplanetary dust distributions, and document a reminder for future spacebased coronagraphic instrument builders.

     

Accommodating ecotourism in multiple use planning of coastal and marine protected areas

Coastal and marine areas the world over provide food, transportation, recreation, and energy resources to increasing numbers of people each year. As demands for these resources rise, the potential for user conflicts is radically heightened. This situation can be avoided or counteracted by instigating proactive multiple use planning. Multiple use zoning plans can only exist in a concrete management framework: marine and coastal protected areas provide just such a foundation. Nature-based or ecotourism can be encouraged in coastal protected areas aimed at achieving sustainability. Well-planned tourism provides economic and political incentives for management and for conservation, and may bring additional benefits to local communities and regional economies. Examples where nature-based tourism has been or is becoming successfully integrated into multiple use planning can be found in Quintana Roo, Mexico; the Lesser Antilles; and Australia, among other areas.     

Abundance versus rates of accumulation in fine-grained strata of the Miocene Santa Barbara Basin,California

Although best known as a deposit rich in silica and organic matter, the Miocene Monterey Formation actually had long-term rates of silica and organic Matter accumulation equal to or lower than values in the underlying and overlying detritus-rich formations in the Santa Barbara coastal area. The factor Mainly influencing the composition of the Monterey Formation in this area was the slow accumulation of terrigenous debris. In contrast, with greater than average silica abundance within the Monterey Formation probably resulted from rapid short-term silica accumulation (of hundreds to tens of thousands years duration) rather than from especially slow accumulation of diluting debris.