Quantifying co-seismic and post-seismic slip on fault scarps and their erosional modification using high-resolution Pleiades optical satellite data and repeat Terrestrial Laser Scanning: the 2016 Mw 6.6 Norcia earthquake (Central Italy)

Fault scarps are a topographical expression of sharp gradients in ground movements in an active tectonic region. However, inferences of slip history and causative earthquake sizes may be biased by co-seismic slip gradients, near-fault deformation, afterslip and erosional processes. To address these biases, I investigate co-seismic and continuing post-seismic deformation of near-fault areas and degradation of fault scarps, using high resolution Pleiades optical satellite images and repeat Terrestrial Laser Scans (TLS). The study area is Monte Vettore in the Apennines, Cental Italy, which has extensive surface ruptures associated with the Mw 6.6 30th October 2016 Norcia earthquake, part of the Central Italy Earthquake Sequence. I combine image correlation techniques with novel median-based filtering to effectively de-noise the Pleiades data, creating Digital Elevation Models (DEMs) from before and after the Norcia earthquake. Those DEMs are then differenced horizontally and vertically. The results identify detail of near-fault co-seismic surface deformation. I jointly invert those data with far-field InSAR (Interferometric Synthetic Aperture Radar) and GNSS (Global Navigation Satellite System) datasets to model co-seismic slip at depth. My model reveals detail of slip transfer from the Monte Vettore fault at shallow depth. This provides insights into the distribution of near-fault co-seismic slip in an area of complex faulting by slip being partitioned onto minor near-surface hanging wall structures, with slip vectors diverging from those at greater depth. The causes of post-seismic alteration or degradation of fault scarps are expected to be tectonic-related after-slip and/or erosion. Combining careful alignment of repeat TLS, use of an ICP (Iterative Closest Point) algorithm, filtering and detrending techniques, I characterise post-seismic deformation at 6 individual sites at ~centimetre scale. This provides insights into how individual factors (e.g. underlying geology, topography, and co-seismic slip gradients and distribution) influence which causes dominate and how degradation develops spatially and temporally. I show that fault scarps are highly variable records of a fault’s slip history. Any assessment of previous slip history using fault scarps as evidence needs to have regard to all those factors.

The morphological characteristics of normal fault traces in the Apennines, Italy

Fault trace ruptures at the Earth’s surface show sinuosity (departure from linear trace morphologies) at a variety of scales in map view, reflecting the growth of the fault, the mechanical stratigraphy of the surrounding geology, and interactions with neighbouring faults. This study uses a combination of new remotely sensed LiDAR and SRTM datasets, and novel techniques which seek to eliminate the distorting effects of topography upon the fault traces. The 2D morphological characteristics of fault traces are mapped and quantified. The relationships between those characteristics and scale of observation and other fault parameters are investigated, to see what insight those relationships afford into fault growth and interaction. By characterising controls of sinuosity at different scales, a better understanding of the effect of fault trace variations on seismic hazard evaluation in active tectonic regions may be obtained. At the whole fault scale, stress interactions between neighbouring faults and between en échelon segments within a fault appear to be the main controls on trace sinuosity. Linear correlations between sinuosity values and fault length and slip rate respectively are weak. However, sinuosity appears to be smoothed out with repeated slip, particularly in central parts of the fault traces. At smaller scale (<100 m), sinuosity is more variable and values spread over a wider range. Local features such as pre-existing fractures/weaknesses appear to be a principal control over deviation. Sinuosity is apparently not much influenced by the controlling factors at the whole fault scale. The current regional extensional stress regime sees normal faults striking broadly SE-NW. Deviation from that pattern may be a significant factor in controlling sinuosity at the whole fault level. Here, anticlockwise deviance from the regional strike appears to coincide with an increase in sinuosity values. The anticlockwise variance brings the faults closer to a previous extensional regime, which left inherited structures trending broadly SW-NE. Those minor structures could be reactivated as transfer faults or segments between en échelon faults or fault segments, particularly in left-stepping situations

Vertebrate Damage Management: The Future of an Evolving Profession

The author argues that an objective of a new group of people taking a systems approach to large wild animal problems should be to manage damage as a cost-reducing role within a total, profitable, long-term system, not necessarily to control the pest. The needs are for well-grounded financial analyses both for customers, the public, the resources, and the well-being of the profession. A point of view is advanced for the need for evolving pest-related operations into a new, unique profession that is involved in a profound way as an element of a cost-effective total land and human resource production system

Maximizing Edge and Coverts for Quail and Small Game

A computer-generated table is presented, enabling the land manger to maximize on a given acreage the length of edge and the number of coverts (or corners where 3 or more cover types come together).Between-field connections are provided for sportsmen and farm machinery. The equations are presented along with diagrams of field layout and graphs of the relative changes in edge and coverts resulting from certain decisions related to management efficiency

Simulation Studies of Quail Hunting Success Associated with Ecological Succession of Planted Pine Stands

A concept paper of a methodology is presented for explaining past populations and predicting future populations of bobwhite quail (Colinus virginianus), as a function of forest changes. The methodology is applicable to large landholdings, regions, and states. It relates, using computer technology, the number of potential covey flushes per 100 acres per day to the age of forest stands or ecological succession curves. By summing quail flush curves over a large area, area-wide yields may be obtained. Flushes are modified by a shooting-quality factor and birds per covey. The computer-generated output tables provide an inventory, a historical overview, and projected populations. The results are useful for making forestry-wildlife tradeoffs, for explaining quail declines or increases as a result of forestry operations, and for improvements in allocating money to wildlife or forestry. The method is based on a similar system for big-game forage in the Pacific Northwest (2) and is now being developed