Results of multiyear studies on the dynamics of pollution of lake Baikal by polycyclic aromatic hydrocarbons in the area waste water discharge from the Baikal Pulp and Paper Plant

New data on the concentration and spatial distribution of the benz(a)pyrene and polycyclic aromatic hydrocarbons in bottom sediments in the testing area of the Baikal Pulp and Paper Plant (BPPP) waste water discharge in 1981–1988 and 2010 are presented in this paper. The bottom sediments in this section of the lake are strongly polluted with polycyclic aromatic hydrocarbons.     

Trojan-type orbits in the system of two gravitational centers with variable masses and separation

Trojan type orbits in the system of two gravitational centers with variable separation are studied within the framework of the restricted problem of three bodies. The backward numerical integration of the equations of motion of the bodies starting in the triangular libration pointsL ₄ andL ₅ (reverse problem) finds the breakdown of librations as the separation decreases because of the mass gain of the smaller component and an approach of the body of negligible, mass to the latter up to the distance below its sphere of action with a relative velocity approximately equal to the escape one on this sphere. The breakdown of librations aboutL ₅ occurs under the mass gain of the smaller component considerably larger than in the case ofL ₄ and implications are made for the asymmetry of the number of librators aboutL ₄ andL ₅ in the solar system (Greeks and Trojans). Other parameters of the libration motion near 1/1 commensurability are obtained, namely, the asymmetry of the libration amplitudes about the triangular points as well as the values of periods and amplitudes within the limits of those for real Trojan asteroids. Trojans could be supposedly, formed inside the Proto-jupiter and escape during its intensive mass loss.     

QuakeSim and the Solid Earth Research Virtual Observatory

We are developing simulation and analysis tools in order to develop a solid Earth Science framework for understanding and studying active tectonic and earthquake processes. The goal of QuakeSim and its extension, the Solid Earth Research Virtual Observatory (SERVO), is to study the physics of earthquakes using state-of-the-art modeling, data manipulation, and pattern recognition technologies. We are developing clearly defined accessible data formats and code protocols as inputs to simulations, which are adapted to high-performance computers. The solid Earth system is extremely complex and nonlinear, resulting in computationally intensive problems with millions of unknowns. With these tools it will be possible to construct the more complex models and simulations necessary to develop hazard assessment systems critical for reducing future losses from major earthquakes. We are using Web (Grid) service technology to demonstrate the assimilation of multiple distributed data sources (a typical data grid problem) into a major parallel high-performance computing earthquake forecasting code. Such a linkage of Geoinformatics with Geocomplexity demonstrates the value of the Solid Earth Research Virtual Observatory (SERVO) Grid concept, and advances Grid technology by building the first real-time large-scale data assimilation grid.     

The impacts of the 2004 hurricanes on hydrology, water quality, and seagrass in the Central Indian River Lagoon, Florida

Between August 14 and September 26, 2004, four tropical weather systems (Charley, Frances, Ivan, and Jeanne) affected the central Indian River Lagoon (IRL). The central IRL received a prodigious amount of rainfall for the 2 mo, between 72 and 83 cm, which is a once-in-50-yr rainfall event. High stream discharges were generated that, combined with wind-suspended sediments, significantly reduced salinities and water transparency. In September, salinities among central IRL segments dropped from 30 psu or more to ≤15 psu, color increased from a low of 10 pcu to ≥100 pcu, and turbidity increased from ≤3 NTU up to 14 NTU. Evidence of the hurricanes' physical effects on seagrasses (burial, no scour) was limited to just one of the more than 25 sites inspected. Within 2 to 3 mo following the hurricane period, most parameters related to water transparency returned to or showed improvement over their prehurricane (February–July 2004) levels. Unseasonably low salinities (<20 psu) and moderately high color (>20 pcu) were observed through spring 2005, largely attributable to a relatively long residence time and a wetter-than-average spring season in 2005. By the end of the study period (July 2006), the central IRL generally showed a continuation of two opposite seagrass trends—an increase in depthlimit coverage but a decline in coverage density—that began before 2004. Also, within a limited reach of the central IRL, there was a temporary shift in species composition in summer 2005 (Ruppia maritima increased asHalodule wrightü decreased). It is likely that the persistently low salinities (not color) in 2004–2005 affected the species composition and coverage density. This study reveals that seagrasses are resilient to the acute effects of hurricanes and underscores the need to reduce chronic, an thropogenic effects on seagrasses.     

Effects of mesoscale physical processes on thin zooplankton layers at four sites along the west coast of the U.S.

Within the coastal marine environment, populations of phytoplankton, zooplankton, bacteria, viruses, and aggregations of marine snow are frequently concentrated beneath the surface in discrete, vertically thin layers. Thin layers range in vertical dimension from a few centimeters to three meters, and have been observed to extend horizontally for kilometers. They appear in the water column episodically and can persist for days. We present some of the results of an investigation of four coastal sites along the west coast of the United States to assess frequency of occurrence of thin layers of zooplankton. Our study sites included coastal sites near East Sound, Washington; Cape Perpetua, Oregon; Monterey Bay, California; and Santa Barbara, California. At each site, we collected several, weeks-long time series of hydrography, current velocity, and acoustic backscatter due to mesozooplankton. Our results show that thin layers were common features at all four sites. Across all study sites, a change in the predominant physical regime, usually precipitated by a change in the wind pattern, corresponded with an absence of thin Zooplankton layers. In order to make a first-order prediction about when thin layers have the possibility of occurring in a coastal environment, we found it useful to examine regional wind and circulation patterns and to determine how they affect stratification in each local environment.     

The Knysna Basin, South Africa: geomorphology, landscape sensitivity and sustainability

The Knysna Basin, a southern Cape catchment, drains into the Knysna estuary. The landscape characteristics are the product of a long geomorphic evolution resulting in high sensitivity to change. Consideration of the geomorphology is followed by examples of impacts on the estuary and adjacent areas. The need for sustainability in the context of development is argued. The paper is a southern African contribution to the landscape sensitivity issue.     

An investigation of the relationship between uniaxial compressive strength and degradation for selected rock types

The relationship between uniaxial compressive strength and degradation was investigated for selected rock types, by using regression analyses to determine whether degradation was a useful predictor of compressive strength. In addition, the effects of aggregate particle size, number of hammer blows during the degradation test, engineering index properties, petrographic characteristics, and water saturation on the compressive strength-degradation relationship were evaluated. The results show that strong inverse relationships exist between compressive strength and degradation (measured on a 9.5-4.75-mm size aggregate) for sandstones and igneous/metamorphic rocks, but that no significant relationship exists for limestones/dolomites. The results also indicate a strong positive correlation between degradation and L.A. abrasion loss and can be used to establish a limit of allowable degradation for practical applications. Engineering index properties do not significantly affect the relationship between compressive strength and degradation but petrographic characteristics are important in explaining the strength and degradation behavior of the rocks studied. Water saturation decreases compressive strength and increases degradation to varying degrees.     

Forests in Limbo: Assessing Costa Rica's Forest and Land Reform Policies

In this article, we consider the stalled implementation of two state policies among recipients of land reform in Costa Rica: the transfer of authority over forests on state agrarian reform lands over to the Ministry of the Environment, and the Rural Development Institute’s requirement to issue land title to the recipients of its land reform projects. To date, neither of these policies is even partially implemented, resulting in both forests and marginalized landholders existing in a state of dual tenure limbo. In this article we draw on document analysis, interviews with policymakers, and interviews with recipients of land reform to determine why these policies have not been implemented. In addition, we assess the potential consequences for forest conservation that this situation has produced by mapping the extent and characteristics of forests that occupy this state of uncertainty.