The normalized topographic method: an automated procedure for gully mapping using GIS

Gully delineation is a critical aspect of accurately determining soil losses but associated methodologies are rarely detailed. Here, we describe a new gully mapping method, the normalized topographic method (NorToM), based on processing digital elevation model (DEM) data, and we assess associated errors when it is applied over a range of geomorphological scales. The NorToM is underpinned by two gully detection variables (normalized slope and elevation) calculated over local windows of prescribed size, and a group of filtering variables. For four study sites, DEMs of gullies were obtained using field and airborne photo‐reconstruction and evaluated using total station and differential global positioning system (dGPS) survey. NorToM provided accurate areal and volume estimates at the individual gully scale but differences increased at the larger gully system and gully network scales. We were able to identify optimal parameters for using the NorToM approach and so confirm that is represents a useful scale‐independent means of gully mapping that is likely to be valid in other environments. Its main limitations are that the normalization process might be time‐consuming at regional scales and the need for a fixed window size when applied to landforms with extreme variations in dimensions. Copyright © 2014 John Wiley & Sons, Ltd.     

The contribution to IHY from the COST296 Action MIERS: Mitigation of Ionospheric Effects on Radio Systems

The objective of the COST296 Action MIERS (Mitigation of Ionospheric Effects on Radio Systems) is to develop an increased knowledge of the effects imposed by the ionosphere on practical radio systems, and for the development and implementation of techniques to mitigate the deleterious effects of the ionosphere on such systems (http://www.cost296.rl.ac.uk). The COST296 Community contributes to the international efforts of IHY with scientific and outreach activities as well. After the realization of a web site hosted by Istituto Nazionale di Geofisica e Vulcanologia (INGV), developed also to promote the ionospheric physics to the open public, the COST296 Community supported an initiative addressed to the pupils of the primary school of several European Countries: the realization of a school-calendar dedicated to the Sun and to the Sun-Earth connections.     

500-year temperature reconstruction in the Mediterranean Basin by means of documentary data and instrumental observations

The paper reports the main results of the EU project Millennium in the Mediterranean area over the last 500 years. It analyses a long series of temperature from Portugal, Spain, France, Italy and Greece. The series are obtained by combining indices from documentary sources from AD 1500 to the onset of regular instrumental observations. There is an ongoing discussion regarding the proper way of combining documentary and instrumental data and how to translate accurately the conventional indices from ??3 to +?3 into modern units, i.e. degree Celsius. This paper produces for the first time a number of early instrumental observations, in some cases (i.e. Italy and France) covering 350 years, including thereby the earliest regular observations after the invention of the thermometer. These Mediterranean data show that anomalous temperatures usually had only a locally limited effect, while only few extreme events had a widespread impact over the whole region, such as the summer of 2003. During the period from 1850 to the present day, the Mediterranean temperature anomaly was close to the Northern Hemisphere in spring and summer, while it was warmer in autumn and winter. Compared with the long-term instrumental records (i.e. 1655 onwards), the recent warming has not exceeded the natural past variability characterized by heating–cooling cycles with no significant long-term trends.     

Galileo PPR observations of Europa: Hotspot detection limits and surface thermal properties

The Galileo photopolarimeter–radiometer (PPR) made over 100 observations of Europa’s surface temperature. We have used these data to constrain a diurnal thermal model and, thus, map the thermal inertia and bolometric albedo over 20% of the surface. We find an increased thermal inertia at mid-latitudes that is widespread in longitude and does not appear to correlate with geology, albedo, or other observables. Our derived thermophysical properties can be used to predict volatile stability across the surface over the course of a day and in planning of infrared instruments on future missions. Furthermore, while observations in the thermal infrared can and have been used to find endogenic activity, no such activity was detected at Europa. We have calculated the detection limits of these PPR observations and find that 100 km² hotspots with temperatures of 116–1200 K could exist undetected on the surface, depending on the location.     

Advancing Global Marine Biogeography Research with Open‐source GIS Software and Cloud Computing

Across many scientific domains, the ability to aggregate disparate datasets enables more meaningful global analyses. Within marine biology, the Census of Marine Life served as the catalyst for such a global data aggregation effort. Under the Census framework, the Ocean Biogeographic Information System was established to coordinate an unprecedented aggregation of global marine biogeography data. The OBIS data system now contains 31.3 million observations, freely accessible through a geospatial portal. The challenges of storing, querying, disseminating, and mapping a global data collection of this complexity and magnitude are significant. In the face of declining performance and expanding feature requests, a redevelopment of the OBIS data system was undertaken. Following an Open Source philosophy, the OBIS technology stack was rebuilt using PostgreSQL, PostGIS, GeoServer and OpenLayers. This approach has markedly improved the performance and online user experience while maintaining a standards‐compliant and interoperable framework. Due to the distributed nature of the project and increasing needs for storage, scalability and deployment flexibility, the entire hardware and software stack was built on a Cloud Computing environment. The flexibility of the platform, combined with the power of the application stack, enabled rapid re‐development of the OBIS infrastructure, and ensured complete standards‐compliance.     

Variations in shoreface progradation and ravinement along the Texas coast, Gulf of Mexico

Shoreface architecture, evolution (mid-Holocene to present) and depths of transgressive ravinement were examined from Sabine Pass, at the Texas–Louisiana border, to South Padre Island, near the Texas–Mexico border, using 30 shoreface transects. Shoreface transects extend out to 16-m water depth, each created from an echo-sounding profile and, on average, seven sediment cores. The shoreface is composed of three broad sedimentological facies: the upper shoreface, composed almost entirely of sand; the proximal lower shoreface, composed of sand with thickly to medium-bedded (50–10 cm) mud; and the distal lower shoreface, composed dominantly of mud with medium- to thinly bedded (20–3 cm) sand. Shoreface architecture and evolution is extremely variable along the Texas coast. Shoreface gradients increase from 2·25 m km^–1 in east Texas to 3·50 m km^–1 in south Texas. Shoreface sands coarsen towards south Texas. East and south Texas shoreface deposits are thin and retrograding whereas central Texas shoreface deposits are thicker and prograding. Central Texas is characterized by stacked shoreface successions, whereas in east Texas, lower shoreface sands are preserved only in offshore banks. Preservation of shoreface deposits is low in south Texas. Although eustatic fluctuations and accommodation space have a strong impact on overall mid-Holocene to present shoreface evolution and preservation potential, along-strike variations in sediment supply and wave energy are the main factors controlling shoreface architecture. The transgressive ravinement surface varies from –6 to –15 m along the Texas coast.     

The use of soil geochemistry in outlining phosphate deposits, northern and southern Venezuela

Phosphate deposits have been outlined in Falcón State (Northern Venezuela) and Táchira State (Southwestern Venezuela) using geochemical soil methods.The phosphate deposits located in Falcón State constitute lenses and masses interbedded with Tertiary limestone and shales. The area is covered by a thick soil with few outerops and the region is characterized by typical tropical rain forest. Soil samples taken every 1000 m across complete stratigraphic sequences were analyzed for P₂O₅ content. An anomalous area with a P₂O₅ content ranging from 3.19% to 9.04% was outlined accompanied by areas with less than 0.83% of P₂O₅. More than 11 million metric tons of commercial phosphatic rock were associated with this anomaly.In Táchira State several stratigraphic sequences of potentially phosphatic rocks with a thick cover of black soil were geochemically investigated. Soil samples taken each 10 m were analyzed for P₂O₅. A sequence of phosphatic rock was outlined showing a P₂O₅ content varying between 7.3% and 9.2%. Apparently the sequence is interbedded with phosphate-poor siliceous rocks showing a P₂O₅ content below 2%.As result of this preliminary investigation, expensive trenching, pitting and drilling works can be carefully planned.     

Marine geophysics along the Gulf of Mexico and the Yucatan peninsula coastal area in Mexico

Marine geophysical studies were carried out along the coastal zone of Mexico in the Atlantic Ocean as part of CICAR and IDOE projects. An area of 200,000 km² was covered by two reconnaissance cruises and a more limited area by tracks for more detailed research. The 15,000 km of track lines include a collection of continuous seismic profiling, bathymetry, gravity and magnetic data.The analyses and correlation of results indicate some local structure features and their relationship to the Neo-volcanic zone and the salt dome belt in the Gulf of Mexico. On the Yucatan area the results show the interaction of continental and oceanic crust at the NW border of the Caribbean Plate.     

Average density of stratigraphic sequences at Vesuvius and Phlaegraean fields at different heights

In order to measure the density of rocks in the Phlacgraean and Vesuvius edifices, appropriately chosen indirect methods, based on a strict relationship between gravity and density, enabled useful data to be obtained. The data can be related to the particular lithological formations of the above volcanic complexes.