Managing erosion-induced problems in NW Mediterranean urban beaches

The applicability of recommendations of the Eurosion project to define a policy to manage coastal erosion has been tested at the “beach” scale in the Mediterranean coast. Thus, a favourable sediment status has been defined for these beaches taking into account their main functions: recreation and protection. Because they act at two different seasons, this status needs to be seasonally defined. For the protection function, the favourable sediment status depends on the level of safety fixed by the manager taking into account the importance of existing infrastructures and, for recreation it depends on the use density of the beach. The concept has been formalized for beach management within a framework where benchmarking plays a crucial role to determine the need of intervention. This has been illustrated for open cell beaches where one of its boundaries can permit variations in the sediment budget and for pocket beaches that act as closed sediment cells.     

Can the low-Activity sun Become Dimmer at Maximum?

After analysing the ratio of sunspot to facular areas along the cycle for solar cycles 12 to 20 we propose two possibilities. One indicates a non-linear behaviour for low-activity cycles and a closer-to-linear behaviour for high-activity cycles, the other one presents a non-linear behaviour for both low- and high-activity cycles and a closer-to-linear behaviour for moderate-activity cycles. Furthermore, we also find within the cycle that during low-activity cycles the Sun becomes brighter as their magnetic activity level increases while for high-activity cycles the opposite occurs, in agreement with previous studies of solar-type stars; another possibility, however, is that when evolving from minimum to maximum both the low- and high-activity Sun may become fainter while the moderate-activity Sun brightens.     

The meteorite of Ensisheim: 1492 to 1992

Abstract— On November 7, 1492, a 127-kg stony meteorite fell at Ensisheim in Alsace after a fireball explosion that was heard for a distance of 150 km over the upper Rhineland. Today, a 56-kg specimen of the stone, an LL6 chondrite with large patches of fusion crust, remains on display in the Hotel de Ville at Ensisheim. This was the earliest witnessed meteorite fall in the West from which pieces are preserved. Initially, the stone's survival depended on the presence of a magistrate at Ensisheim who forbade the removal of pieces, which had begun apace as soon as a crowd gathered and pulled the stone out of a 1-m hole in a wheat field. He ordered the stone brought into the city to await the arrival of King Maximilian, son of the Holy Roman Emperor Friedrich III, who was approaching with his army. In nearby Basel, broadsheets were printed within weeks bearing the story in Latin and German verses by the eminent poet, Sebastian Brant, who turned the sheets into propaganda tracts by claiming the stone as a portent of victory and admonishing Maximilian to make war on the French without delay. Maximilian declared the stone to be a sign of divine favor and ordered it to be preserved in the Ensisheim parish church. The stone grew in fame when Maximilian won his impending battle with the French, but strange new elements entered the story as it was repeated over the years in books and chronicles. Through centuries of battle and political changes, the stone remained in the church until 1793 when French revolutionaries transferred it to a new National Museum in Colmar. There, many pieces were taken for chemical analyses during the birth of the meteoritics at the turn of the 19th century. In 1803 the stone was returned to the Ensisheim church where it outlasted the structure itself which collapsed in 1854. This paper traces the history of the stone itself and people's responses to it through the 500 years since the fall at Ensisheim.     

Ernst Florens Friedrich Chladni (1756–1827) and the origins of modern meteorite research

Abstract— In 1794, Ernst F. F. Chladni published a 63-page book Über den Ursprung der von Pallas gefundenen und anderer ihr änlicher Eisenmassen und über einige damit in Verbindung stehende Naturerscheinungen in which he proposed that meteor-stones and iron masses enter the atmosphere from cosmic space and form fireballs as they plunge to Earth. These ideas violated two strongly held contemporary beliefs: (1) fragments of rock and metal do not fall from the sky, and (2) no small bodies exist in space beyond the Moon. From the beginning, Chladni was severely criticised for basing his hypotheses on historical eyewitness reports of falls which others regarded as folk tales and for taking gross liberties with the laws of physics. Eight years later, the study of fallen stones and irons was established as a valid field of investigation. Today, some scholars credit Chladni with founding meteoritics as a science; others regard his contributions as scarcely worthy of mention. Writings by his contemporaries suggest that Chladni's book alone would not have led to changes of prevailing theories; thus, he narrowly escaped the fate of those scientists who propose valid hypotheses prematurely. However between 1794 and 1798, four falls of stones were witnessed and widely publicized. There followed a series of epoch-making analyses of fallen stones and “native irons” by the chemist Edward C. Howard and the mineralogist Jacques-Louis de Bournon. They showed that all the stones were much alike in texture and composition but significantly different from the Earth's known crustal rocks. Of primary importance was Howard's discovery of nickel in the irons and the metal grains of the stones. This linked the two as belonging to the same natural phenomenon. The chemical results, published in 1802 February, persuaded leading scientists in England, France, and Germany that bodies fall from the sky. Within a few months, chemists in France reported similar results and a new field of study was inaugurated internationally—although opposition lingered on until 1803 April, when nearly 3,000 stones fell at L'Aigle in Normandy and transformed the last skeptics into believers. Chladni immediately received full credit for his hypothesis of falls, but decades passed before his linking of falling bodies with fireballs received general acceptance. His hypothesis of their origin met with strong resistance from those who argued that stones formed within the Earth's atmosphere or were ejected by lunar volcanoes. After 1860, when both of these hypotheses were abandoned, there followed a century of debate between proponents of an interstellar vs. a planetary origin. Not until the 1950s did conclusive evidence of their elliptical orbits establish meteorite parent bodies as members of the solar system. Thus, nearly 200 years passed before the questions of origin that Chladni raised finally were resolved.     

THE METEORITICAL SOCIETY: 1933 to 1993

Abstract— In August, 1933, at the Field Museum of Natural History in Chicago, The Society for Research on Meteorites was founded with an enrollment of 57 charter members and Frederick C. Leonard and Harvey H. Nininger as the first President and Secretary-Treasurer, respectively. Within five years, the Society had doubled in size, with members from the U.S.A. and ten other nations. Annual meetings were suspended during World War II (1942 through 1945) and when it reconvened in 1946 the members adopted the name “The Meteoritical Society”. By that time personal and professional antagonisms had arisen that threatened to fragment the Society and led, in 1949, to the resignation of Nininger and his wife. Throughout the 1950s the Society was widely regarded as a small, disorganized and essentially moribund organization. Revitalization of the Society began in the early 1960s after the advent of the Space Age when the Society steadily gained members with expertise in mineralogy, petrology, isotope geochemistry, electron microprobe and neutron activation analysis, and impact dynamics. When Nininger was persuaded rejoin in 1963, he found a renewed Society. In the election year of 1966 a group of youthful insurgents nominated an alternate slate to that proposed by the Council and won every contested seat on the Council except that of the Editor. The Society's first publication Contributions of the Society for Research on Meteorites was published as a section of Popular Astronomy and from 1935 to 1946 reprints of the items (articles, reviews, and notices) were bound and distributed separately each year. When the Society changed its name in 1946, its journal became Contributions of the Meteoritical Society, which continued publication until Popular Astronomy ceased publication in 1952. A new journal, Meteoritics, was instituted in 1953. After 1956, its publication lapsed for six years but began again in 1963 and has continued under the leadership of four successive editors becoming one of the most frequently cited geoscience journals. In 1970, the Society also became a co-sponsor with The Geochemical Society of Geochimica et Cosmochimica Acta, but the future of this arrangement remains in doubt. In 1938, the Society had gained considerable prestige by its acceptance as a full Affiliate of the American Association for the Advancement of Science, but in view of its increasingly international membership and activities the Society terminated its affiliation with the AAAS in 1976. Again in response to its international status, in 1992 The Meteoritical Society affiliated with the International Union of Geological Sciences. The Society held its first annual meeting outside North America at the Universität Tübingen in West Germany in 1971. Subsequently, it met in Europe every second year until 1990, when it met at Perth in Western Australia. During the 1980s, the membership of the Society grew to more than 900 and the annual meetings attracted between 300 and 450 participants. As meteoritical research continues to probe the borderlands with astrophysics, planetary science, and terrestrial geology, and as younger members assume leadership roles, a productive future seems assured for both meteoritical science and The Meteoritical Society.     

Macrobenthic community response to copper in Shelter Island Yacht Basin, San Diego Bay, California

We examined Cu contamination effects on macrobenthic communities and Cu concentration in invertebrates within Shelter Island Yacht Basin, San Diego Bay, California. Results indicate that at some sites, Cu in sediment has exceeded a threshold for “self defense” mechanisms and highlight the potential negative impacts on benthic faunal communities where Cu accumulates and persists in sediments. At sites with elevated Cu levels in sediment, macrobenthic communities were not only less diverse but also their total biomass and body size (individual biomass) were reduced compared to sites with lower Cu. Cu concentration in tissue varied between species and within the same species, reflecting differing abilities to “regulate” their body load. The spatial complexity of Cu effects in a small marina such as SIYB emphasizes that sediment-quality criteria based solely on laboratory experiments should be used with caution, as they do not necessarily reflect the condition at the community and ecosystem levels.     

Are metal-induced hypersensitivities in harbor seals associated with liver function?

Environmental exposure to metals is believed to affect marine mammal health adversely including immunosuppression or acute as well as chronic inflammatory processes leading to hypersensitivities or autoimmune diseases. Metal-specific hypersensitivities were found in several pinnipeds of the North Sea. However, hypersensitivity is a complex phenomenon whose characteristics are still not completely understood; in particular, effects on health are not well established. In the present study, we compared basic hematological and biochemical parameters of seals with and without metal-specific hypersensitivities. We found altered hematological parameters and liver enzyme patterns in seals with a metal-induced hypersensitivity, including a reduction in macrophages, an increase in lymphocytes, and elevated levels of lactate dehydrogenase. These findings support the suggestion of a chronic influence of metal pollutants on the health of marine mammals of the North Sea.     

Geoacoustic character,sedimentology and chronology of a cross-shelf Holocene sediment deposit off Cabo Frio,Brazil (southwest Atlantic Ocean)

The Cabo Frio region in the state of Rio de Janeiro, southeast coast of Brazil, is characterized by a local coastal upwelling system and converging littoral sediment transport systems that are deflected offshore at Cabo Frio, as a consequence of which a thick cross-shelf sediment deposit has developed over time. To investigate the evolution of this muddy deposit, geophysical, sedimentological and geochemical data from four sediment cores (3.8–4.1 m in length) recovered in water depths between 88 and 141 m were analyzed. The high-resolution seismic data show variable sediment thicknesses ranging from 1 to 20 m, comprising two sedimentary units separated by a high-impedance layer at a depth of about 10 m below the seafloor at the coring sites. According to the available age datings, the upper sedimentary unit is late Pleistocene to Holocene in age, whereas the lower unit (not dated) must, by implication, be entirely Pleistocene in age. The boomer-seismic reflection signal can be divided into three echo-types, namely transparent (inner shelf), stratified (middle shelf) and reflective (outer shelf), each type seemingly related to the local sediment composition. The upper 4 m of the upper sedimentary unit is dominated by silty sediment on the middle shelf, and by upward-fining sediments (silty sand to sandy silt) on the inner and outer shelf. The downcore trends of P-wave velocity, gamma-ray density and acoustic impedance are largely similar, but generally reversed to those of water and organic carbon contents. Total organic carbon contents increase with decreasing mean grain size, periodic fluctuations suggesting temporal changes in the regional hydrodynamics and primary productivity fuelled by the local upwelling system. The reconstruction of sedimentation rates in the course of the Holocene is based on 35 AMS age datings of organic material recovered from variable downcore depths. These range from a maximum of 13.3 cm/decade near the base of the inner shelf core (7.73–7.70 ka BP) to generally very low values (<0.11 cm/century) over the last thousand years in all cores. Over the last 6 ka there appear to have been three distinct sedimentation peaks, one between 6 and 5 ka BP, another between 4 and 3 ka PB, and one around 1 ka BP. Due to different time intervals between dates, not every peak is equally well resolved in all four cores. Based on the similar sedimentology of the inner and outer shelf cores, an essentially identical sedimentation model is proposed to have been active in both cases, albeit at different times. Thus, already during the last glacial maximum, alongshore sediment transport was deflected offshore by a change in shoreline orientation caused by the Cabo Frio structural high. The source of terrigenous material was probably a barrier-island complex that was subsequently displaced landward in the course of sea-level rise until it stabilized some 6.5 ka BP along the modern coast.     

Cultivating the sustainable city: urban agriculture policies and gardening projects in Minneapolis,Minnesota

In the past 20 years, municipal governments across the United States have increasingly tried to incorporate environmental efforts into city business and policies. Urban sustainability has become the key concept around which such activities are organized. Official sustainability plans are most often implemented through indicators and metrics. In Minneapolis, Minnesota, urban gardening, in a variety of forms, has been the focus of ongoing citizen- and NGO-led environmental efforts, as well as municipal measures of sustainability. Here, debates around the recent adoption of a city urban agriculture policy, as well as a program to encourage the installation of raingardens in neighborhoods across the city, reveal some of the rich variations in gardening practices and spaces. These far exceed the relatively narrow official focus on sustainability indicators. Better understanding how urban sustainability initiatives might work with, but also move beyond, indicators may provide directions toward wider visions of sustainable urban life.