Estimation of dynamic friction and movement history of large landslides

We performed seismic waveform inversions and numerical landslide simulations of deep-seated landslides in Japan to understand the dynamic evolution of friction of the landslides. By comparing the forces obtained from a numerical simulation to those resolved from seismic waveform inversion, the coefficient of friction during sliding was well-constrained between 0.3 and 0.4 for landslides with volumes of 2–8 ×10⁶ m³. We obtained similar coefficients of friction for landslides with similar scale and geology, and they are consistent with the empirical relationship between the volume and dynamic coefficient of friction obtained from the past studies. This hybrid method of the numerical simulation and seismic waveform inversion shows the possibility of reproducing or predicting the movement of a large-scale landslide. Our numerical simulation allows us to estimate the velocity distribution for each time step. The maximum velocity at the center of mass is 12–36 m/s and is proportional to the square root of the elevation change at the center of mass of the landslide body, which suggests that they can be estimated from the initial DEMs. About 20% of the total potential energy is transferred to the kinetic energy in our volume range. The combination of the seismic waveform inversion and the numerical simulation helps to obtain the well-constrained dynamic coefficients of friction and velocity distribution during sliding, which will be used in numerical models to estimate the hazard of potential landslides.     

Ex situ cultivation of Aplysinaaerophoba close to in situ conditions: ecological, biochemical and histological aspects

Sponges provide the largest number of biologically active natural products known from the marine environment and continue to be a very well studied phylum of marine fauna. The Mediterranean sponge Aplysina aerophoba accumulates brominated isoxazoline alkaloids such as Aplysinamisin-1, Aerophobin-2, Isofistularin-3 and the biotransformation product Aeroplysinin-1, which possesses, for example, antibiotic and cytotoxic properties. Until now, it is still being discussed which organisms – the sponge itself or associated microorganisms – are responsible for metabolite production. For cultivating Aplysina individuals under ex situ conditions, we surveyed relevant ecological factors in situ and controlled them in our aquarium system. We maintained A. aerophoba for more than 9 months and analysed changes of metabolite content and composition, microbial association as well as morphology in situ and ex situ under different light exposure. Although sponges showed slight reduction during maintenance, ex situ cultivation similar to in situ conditions provides a promising method to keep sponges and obtain their bioactive metabolites.     

Water level variations in the Neuse and Pamlico Estuaries,North Carolina due to local and remote forcing

Water level time series records from the Neuse and Pamlico River Estuaries were statistically compared to local and distant wind field data, water level records within the Pamlico Sound and also coastal ocean sites to determine the relative contribution of each time series to water levels in the Neuse and Pamlico Estuaries. The objectives of this study were to examine these time series data using various statistical methods (i.e. autoregressive, empirical orthogonal function analysis (EOF), exploratory data analysis (EDA)) to determine short- and long-time-scale variability, and to develop predictive statistical models that can be used to estimate past water level fluctuations in both the Neuse Estuary (NE) and Pamlico Estuary (PE). Short- and long-time-scale similarities were observed in all time series of estuarine, Pamlico Sound and subtidal coastal ocean water level and wind component data, due to events (nor'easters, fronts and tropical systems) and seasonality. Empirical orthogonal function analyses revealed a strong coastal ocean and wind field contribution to water level in the NE and PE. Approximately 95% of the variation was captured in the first two EOF components for water level data from the NE, sound and coastal ocean, and 70% for the PE, sound and coastal ocean. Spectral density plots revealed strong diurnal signals in both wind and water level data, and a strong cross correlation and coherency between the NE water level and the North/South wind component. There was good agreement between data and predictions using autoregressive statistical models for the NE (R² = 0.92) and PE (R² = 0.76). These methods also revealed significant autoregressive lags for the NE (days 1 and 3) and for the PE (days 1, 2 and 3). Significant departures from predictions are attributed to local meteorological and hydrological events. The autoregressive techniques showed significant predictive improvement over ordinary least squares methods. The results are considered within the context of providing long time-scale hindcast data for the two estuaries, and the importance of these data for multidisciplinary researchers and managers.     

Managing by principle: A critical analysis of the European principles of Integrated Coastal Zone Management (ICZM)

A set of eight principles is contained in the European Recommendation on Integrated Coastal Zone Management. The principles have been adopted with the minimum of critical review. The six core principles form two groups, one concerned with strategic goals and one that has a local focus. The principles are presented as a menu of free-standing options, with no prioritization either within or between groups. This can produce irreconcilable differences in strategy. The principles require clarification, prioritization of the strategic principles and recognition that they are an indivisible integrated set which should not be used to select principles to advance a particular agenda.