On the Mediterranean conveyor belt system

The Mediterranean Sea is a semi-enclosed sea, connected to the Atlantic Ocean through the Gibraltar Strait and subdivided in two different regions by the Sicily Strait. The geographical extension of the basin, the surface heat flux, and the water inflow from the Gibraltar Strait are some of the basic factors determining its horizontal and vertical circulation. In the Mediterranean strong salinity and temperature zonal gradients contribute to maintain the zonal-vertical circulation, while meridional-vertical cells are equally forced by winds and deep water mass formation in three regions, the Gulf of Lyon, the southern Adriatic and the Cretan Sea areas. The objective of this thesis is to study how these cells combine together to form the Mediterranean conveyor belt system. This has never been attempted before so the conclusions are necessarily preliminary. In the first part we discuss the vertical zonal and meridional circulation by reconstructing the Wust Mediterranean vertical salinity and temperature structures in an attempt to evaluate the water mass structure consistent with modern data. Our results confirm that Wust depicted vertical circulation from scarce data is reproduced by the past 27 years observations. The structure of both meridional and zonal circulations was discussed using velocity vertical streamfunctions with two different methods. The first one, eulerian, allowed us to observe vertical structures that were already reported in the literature. Recent studies in the Atlantic Ocean have shown that gyres and eddies have an important influence in the isopycnal vertical circulation. This is called the residual circulation which was computed in this study for the first time. A possible interpretation of horizontal connection between the meridional and zonal cells was discussed using horizontal streamfunction. In the last part of the thesis we have been developing an idealized numerical model to study the vertical circulation in the Mediterranean.

Temperatures, salinity, wind speed, grain sizes and foraminifera abundance in the Great Belt Channel, western Baltic Sea

The Great Belt, the largest inlet to the Baltic Sea, has a deep and well defined channel system. A distinct thermohaline layer at roughly 18 to 20 m of water depth separates the saltier and generally cooler deeper North Sea water from the brackish and warmer surface water. It is practically a current dominated area, with the strongest bottom currents due to prolonged west winds. The size and shape of the surface sediments and their grain size distributions show a close relationship with the prevailing hydrographical conditions. Southerly current marks predominate while northerly directions are confined to 10 to 14 m of water depth. The degree of bioturbation is highest in the uppermost sedimentary cover where practically all original stratification has been destroyed. Various bioturbate structures have been identified with the fauna. Coiling ratios of Ammonia beccarii (Linnaeus) have been successfully applied for correlation in the postglacial sediments of the early Littorina Transgression. The succession shows that in the Boreal brackish water conditions were probably followed by peat and limnic sediments as the sea regressed. With the Littorina Transgression, the sea again entered the area and high sedimentation rates resulted in the major deposits of the Great Belt. At least for the last 4000 years, sedimentation rates had been very low. Present day currents sweep out the sediments, mainly to the southern marginal areas.

Structural evolution of the Lesser Himalayan fold-thrust belt of west central Nepal

The Lesser Himalayan fold-thrust belt on the south flank of the Jajarkot klippe in west central Nepal was mapped in detail between the Main Central thrust in the north and the Main Boundary thrust in the south. South of the Jajarkot klippe, the fold-thrust belt involves sandstone, shale and carbonate rocks that are unmetamorphosed in the foreland and increase in metamorphic grade with higher structural position to sub-greenschist facies towards the hinterland. The exposed stratigraphy is correlative with the Proterozoic Ranimata, Sangram, Galyang, Syangia Formations and Lakharpata Group of Western Nepal and overlain by the Paleozoic Tansen and Kali Gandaki Groups. Based on field mapping and cross-section construction, three distinct thrust sheets were identified separated by top-to-the-south thrust faults. From the foreland (south) to the hinterland (north), the first thrust sheet in the immediate hanging wall of the Main Boundary thrust defines an open syncline. The second thrust sheet contains a very broad synformal duplex, which is structurally stacked against the third thrust sheet containing a homoclinal panel of the oldest exposed Proterozoic stratigraphy. Outcrop scale folds throughout the study area are predominantly south vergent, open, and asymmetric reflecting the larger regional scale folding style, which corroborate the top-to-the-south deformation style seen in the faults of the region. Field techniques were complemented with microstructural and quartz crystallographic c-axis preferred orientation analyses using a petrographic microscope and a fabric analyzer, respectively. Microstructural analysis identified abundant strain-induced recrystallization textures and occasional occurrences of top-to-the-south shear-sense indicators primarily in the hinterland rocks in the immediate footwall of the Main Central Thrust. Top-to-the-south shearing is also supported by quartz crystallographic c-axis preferred orientations. Quartz recrystallization textures indicate an increase in deformation temperature towards the Main Central thrust. A line balance estimate indicates that approximately 15 km of crustal shortening was accommodated by folding and faulting in the fold-thrust belt south of the Jajarkot klippe. Additionally, estimations of shortening velocity suggest that the shortening velocity operating in this section of the fold-thrust belt between 23 to 14 Ma was slower than what is currently observed as a result of the ongoing deformation of the Sub-Himalayan fold-thrust belt.

Gravity collapse structures in the Central Precordillera fold-andthrust belt, Argentina

Several landforms found in the fold-and-thrust belt area of Central Precordillera, Pre-Andes of Argentina, which were often associated with tectonic efforts, are in fact related to non-tectonic processes or gravitational superficial structures. These second-order structures, interpreted as gravitational collapse structures, have developed in the western flank of sierras de La Dehesa and Talacasto. These include rock-slides, rock falls, wrinkle folds, slip sheets and flaps, among others; which together constitute a monoclinal fold dipping between 30º and 60º to the west. Gravity collapse structures are parallel to the regional strike of the Sierra de la Dehesa and are placed in Ordovician limestones and dolomites. Their sloping towards the west, the presence of bed planes, fractures and joints; and the lithology (limestone interbedded with incompetent argillaceous banks) would have favored their occurrence. Movement of the detached structures has been controlled by lithology characteristics, as well as by bedding and joints. Detachment and initial transport of gravity collapse structures and rockslides in the western flank of the Sierra de la Dehesa were tightly controlled by three structural elements: 1) sliding surfaces developed on parallel bedded strata when dipping >30° in the slope direction; 2) Joint’s sets constitute lateral and transverse traction cracks which release extensional stresses and 3) Discontinuities fragmenting sliding surfaces.  Some other factors that could be characterized as local (lithology, structure and topography) and as regional (high seismic activity and possibly wetter conditions during the postglacial period) were determining in favoring the steady loss of the western mountain side in the easternmost foothills of Central Precordillera.

Seat Belt Convictions by County of Occurrence - 2011 to 2014, May 8, 2015

Convictions of seat belt violations by county for the state of Iowa from 2011-2014.

2000 Seat Belt Usage Survey, September 13, 2001

The good news is that safety belt usage on municipal road systems (city streets) increased 1.07 percent. This is encouraging since more than 45 percent of all motor vehicle crashes occur on city streets, and usage on the municipal road system has consistently been the lowest of the road systems studied. In communities where usage is good, enforcement and public education must be maintained in order to improve usage further; in communities where usage is still low, enforcement and public education must both be increased. Usage on the primary system (U.S. or state highways) rose 1.01 percent from the previous year. This is also welcome news because almost half of all fatalities (49 percent) occur on the primary road system. There was a decline in interstate belt use (-1.45 percent). Despite this decrease interstate usage is still traditionally the highest of all roadway categories presumably because the longer trips, higher travel speeds and large number of vehicles cause drivers to assume there is greater risk.

1999 Seat Belt Usage Survey, March 15, 2000

The 78 percent seat belt usage rate in 1999 (up 7 percent since 1992) reflects active enforcement and education efforts that have occurred in Iowa during the last few years. Through continuing education of the public, an active "Life Toll" campaign, seat belt enforcement, and other cooperative efforts between state and local law enforcement, Iowa will strive to increase the use of seat belts and save lives on Iowa roadways.

1998 Seat Belt Usage Survey, February 18, 1999

The 78 percent seat belt usage rate in 1999 (up 7 percent since 1992) reflects active enforcement and education efforts that have occurred in Iowa during the last few years. Through continuing education of the public, an active "Life Toll" campaign, seat belt enforcement, and other cooperative efforts between state and local law enforcement, Iowa will strive to increase the use of seat belts and save lives on Iowa roadways.

2001 Seat Belt Usage Survey, April 23, 2003

The 81 percent seat belt usage rate in 2001 (up 10 percent since 1992) reflects active enforcement and education efforts that have occurred in Iowa during the last few years. Through continuing education of the public, an active "Life Toll" campaign, seat belt enforcement, and other cooperative efforts between state and local law enforcement, Iowa will strive to increase the use of seat belts and save more lives on Iowa roadways.

2002 Seat Belt Usage Survey, February 26, 2003

The 82 percent seat belt usage rate in 2002 (up 11 percent since 1992) reflects active enforcement and education efforts that have occurred in Iowa during the last few years. Through continuing education of the public, an active "Life Toll" campaign, seat belt enforcement, and other cooperative efforts between state and local law enforcement, Iowa will strive to increase the use of seat belts and save more lives on Iowa roadways.

2004 Seat Belt Usage Survey, August 15, 2005

The 86.4 percent safety-belt usage rate in 2004 (an increase of 13 percent since 1994) reflects active enforcement and education efforts that have occurred in Iowa over the course of the last decade. Through continuing education of the public with programs in the school and communities, the “Click it or Ticket” campaign, an active “Life Toll” campaign, year-long safety belt enforcement, and other cooperative efforts between state and local law enforcement, Iowa will strive to increase the use of safety belts and save more lives on Iowa roadways.

2005 Seat Belt Usage Survey, June 12, 2006

During the spring and summer of 2005, two surveys were taken of motor vehicle drivers’ and passengers’ seat belt usage. These surveys are before and after parts of the “Click it or Ticket” education and enforcement campaign. The whole project starts with a pre-campaign survey followed by the four-week public information, education and enforcement campaign. Finally, the postcampaign survey is taken to test the effectiveness of the education and enforcement campaign. In the pre-campaign survey of seat belt usage, the usage/non-usage of 15,444 front seat occupants of cars, vans, SUVs and pickups were observed at 100 locations. In the post-campaign survey of seat belt usage, 15,731 observations were made of front seat occupants of cars, vans, SUVs and pickups. The day of the week and time of day the observations took place were selected for each site using a random number generation computer program.

2006 Seat Belt Usage Survey, April 28, 2011

Surveys were taken of motor vehicle drivers’ and passengers’ seat belt usage. These surveys are before and after parts of the “Click it or Ticket” education and enforcement campaign. The whole project starts with a pre-campaign survey followed by the four-week public information, education and enforcement campaign. Finally, the postcampaign survey is taken to test the effectiveness of the education and enforcement campaign.

2007 Seat Belt Usage Survey, April 28, 2011

Surveys were taken of motor vehicle drivers’ and passengers’ seat belt usage. These surveys are before and after parts of the “Click it or Ticket” education and enforcement campaign. The whole project starts with a pre-campaign survey followed by the four-week public information, education and enforcement campaign. Finally, the postcampaign survey is taken to test the effectiveness of the education and enforcement campaign.