Luis E Marin
Universidad Nacional Autónoma de México, Natural Resources, Faculty Member
We use the G.O.D. criteria to evaluate the vulnerability of the Yaqui Valley aquifer from drill hole data and water table maps. The pollutant loads are identified and quantified and the aquifer pollution risk was calculated from the... more
We use the G.O.D. criteria to evaluate the vulnerability of the Yaqui Valley aquifer from drill hole data and water table maps. The pollutant loads are identified and quantified and the aquifer pollution risk was calculated from the aquifer vulnerability and the pollution load. The most vulnerable zones are in the West, and the most important contributions of pollutants are from industrial, agricultural, livestock and population centers. The highest aquifer pollution risk areas are Central, West and East.
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Una base corta de dos estaciones fue medida tres veces de manera repetitiva durante un período de tres días del 21 al 23 de marzo para determinar la precisión del componente vertical utilizando un Sistema de Posicionamiento Global... more
Una base corta de dos estaciones fue medida tres veces de manera repetitiva durante un período de tres días del 21 al 23 de marzo para determinar la precisión del componente vertical utilizando un Sistema de Posicionamiento Global Diferencial. Los tiempos de ocupación duraron de 270-600 minutos (de cuatro a diez horas). La ecuación que mejor define esta línea para el componente vertical es y=0.6397t-2.009, donde y es el error en metros y t es el tiempo en minutos.
Differences in elevation for a set of 12 different points were determined using a Total Station and a DGPS three receivers with occupation times of 90 minutes per station). A comparison between both sets of elevation values shows... more
Differences in elevation for a set of 12 different points were determined using a Total Station and a DGPS three receivers with occupation times of 90 minutes per station). A comparison between both sets of elevation values shows differences of two to 36 millimeters for a maximum baseline of 2,420 meters. These results show that differential GPS surveys may be used to determine differences in elevation using the differential GPS technique.
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Nitrate pollution is a worldwide problem in groundwater, as it may limit water supply and increase health risk when high concentrations are present. The North Maresme coastal alluvial groundwater-dependent agrosystem, one of the most... more
Nitrate pollution is a worldwide problem in groundwater, as it may limit water supply and increase health risk when high concentrations are present. The North Maresme coastal alluvial groundwater-dependent agrosystem, one of the most heavily nitrate polluted aquifers in Spain, is located 70 km northeast from Barcelona. Field monitoring campaigns performed in this aquifer yielded nitrate concentrations up to ten times the permitted limit for drinking water suggested by the World Health Organization (50 mg/l), with a maximum concentration of 567 mg/l and a mean of 137.5 mg/l. Nitrate contamination was quantified by means of a mass balance, taking into account the main hydrogeological and anthropogenic processes that control the behavior of this ion in the aquifer, such as recharge, groundwater extraction, irrigation and fertilizer application to crops. Nitrate balance is an integrative approach for assessing nitrate loading based on linking different sources of nitrates to a groundwat...
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Research Interests: Geophysics and GEOFISICA
Research Interests: Geophysics and Geofísica
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ABSTRACT
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The error from three different surveying techniques- level, hand-held barometer, and hand-held GPS-were compared in terms of accuracy and cost effectiveness for hydrogeological studies by surveying a four-kilometer circuit within the... more
The error from three different surveying techniques- level, hand-held barometer, and hand-held GPS-were compared in terms of accuracy and cost effectiveness for hydrogeological studies by surveying a four-kilometer circuit within the campus of the Uni versidad Nacional Autonoma de Mexico.The polygon was surveyed once with the level and the barometer, and twice with GPS. Vertical errors were 17 mm, 13 meters and 114 meters, for the level, barometer and GPS, respectively. Of the three options, the first is by fa r the most expensive. Thus, the preferred method for height determinations continues to be the level, even if it is the more expensive opt ion.
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The error from three different surveying techniques- level, hand-held barometer, and hand-held GPS-were compared in terms of accuracy and cost effectiveness for hydrogeological studies by surveying a four-kilometer circuit within the... more
The error from three different surveying techniques- level, hand-held barometer, and hand-held GPS-were compared in terms of accuracy and cost effectiveness for hydrogeological studies by surveying a four-kilometer circuit within the campus of the Universidad Nacional Autonoma de Mexico.The polygon was surveyed once with the level and the barometer, and twice with GPS. Vertical errors were 17 mm, 13 meters and 114 meters, for the level, barometer and GPS, respectively. Of the three options, the first is by far the most expensive. Thus, the preferred method for height determinations continues to be the level, even if it is the more expensive option.
We identified a ~4-micrometer-long, ~1 x 10^-10 g "nugget" of Ir metal in a melt rock sample from the Chicxulub impact basin. This particle, which consists of an aggregate of subhedral Ir metal grains surrounded by a thin... more
We identified a ~4-micrometer-long, ~1 x 10^-10 g "nugget" of Ir metal in a melt rock sample from the Chicxulub impact basin. This particle, which consists of an aggregate of subhedral Ir metal grains surrounded by a thin coating of silicate, was isolated in the course of our efforts to better understand the partitioning of projectile material between crater deposits and ejecta in large meteorite impact events. In addition to confirming earlier reports of Ir in melt rock and melt breccia within the K-T boundary source crater, the results of our search for physically identifiable carriers of meteoritic components provide additional evidence for extreme fractionation of siderophile elements and their concentration in sparsely disseminated trace phases.
The water governance elements for Mexico are presented, using the trialogue model. Three examples of water governance for Aguascalientes, Guerrero and the Yucatan are given. In all three cases, there is a strong presence of the federal... more
The water governance elements for Mexico are presented, using the trialogue model. Three examples of water governance for Aguascalientes, Guerrero and the Yucatan are given. In all three cases, there is a strong presence of the federal government. In two cases, where there is a stronger science or society element, there is improved water governance. Activities of the Water Network of the Mexican Academy of Sciences, that are enhancing the science - society, and science - government interfaces are presented. This paper shows how a group of scientists are trying to improve the water governance in Mexico through the development of stronger interfaces between science and society so that, eventually, a better informed society may hold its policy-makers accountable.
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Mexico has two kinds of groundwater problems. The first, which is common to many nations, includes groundwater contamination, saltwater intrusion, and severe drawdown in aquifers. The second, which amplifies effects of the physical... more
Mexico has two kinds of groundwater problems. The first, which is common to many nations, includes groundwater contamination, saltwater intrusion, and severe drawdown in aquifers. The second, which amplifies effects of the physical problems, is a lack of trained ...
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Six units of YAX-1 impact breccias are tentatively interpreted, from top (795 m) to bottom (895 m), as (1) redeposited suevite, (2) suevite, (3/4) a "nuee ardente/ash-flow"-like deposit, (5) a fragmented melt rock (melt... more
Six units of YAX-1 impact breccias are tentatively interpreted, from top (795 m) to bottom (895 m), as (1) redeposited suevite, (2) suevite, (3/4) a "nuee ardente/ash-flow"-like deposit, (5) a fragmented melt rock (melt breccia), and (6) a carbonate melt-rich breccia.
... Tectonophysics 237 (1994) 105-112 Professors Antonio Camargo, Maureen Steiner and Masaru Kono for useful comments and dis-cussion on this work. ... Hildebrand, AR, Penfield, GT, Kring, DA, Pilkington, M., Camargo, A., Jacobsen, SB and... more
... Tectonophysics 237 (1994) 105-112 Professors Antonio Camargo, Maureen Steiner and Masaru Kono for useful comments and dis-cussion on this work. ... Hildebrand, AR, Penfield, GT, Kring, DA, Pilkington, M., Camargo, A., Jacobsen, SB and Boynton, WV, 1991. ...
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Abstract Imagine witnessing the impact of a 10 km-sized comet or asteroid onto a broad expanse of sea just off the Yucatan peninsula of Mexico. The bolide, a brilliant fireball traveling at speeds of 15 to 20 km/s, would melt about 20,000... more
Abstract Imagine witnessing the impact of a 10 km-sized comet or asteroid onto a broad expanse of sea just off the Yucatan peninsula of Mexico. The bolide, a brilliant fireball traveling at speeds of 15 to 20 km/s, would melt about 20,000 km 3 of rock and excavate a ...
... Authors: Neuman, BR; Merediz Alonso, G.; Rebolledo Vieyra, M.; Marin, L.; Supper, R.; Bauer-Gottwein, P. ... The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population... more
... Authors: Neuman, BR; Merediz Alonso, G.; Rebolledo Vieyra, M.; Marin, L.; Supper, R.; Bauer-Gottwein, P. ... The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population in the Mexican federal state of Quintana Roo ...
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Hydrochemical data are presented to describe the process that modifies the groundwater quality in northwest Yucatán. Solution of almost pure carbonate rocks, conservative mixing with seawater and ionic interchange in clayey limestone of... more
Hydrochemical data are presented to describe the process that modifies the groundwater quality in northwest Yucatán. Solution of almost pure carbonate rocks, conservative mixing with seawater and ionic interchange in clayey limestone of middle Eocene are found. Groundwater flow is from the central zone of the study area outward. New observations confirm earlier studies on proposed conservation measures in the area. Brackish water is found several kilometers inland. Salinity increase is due to saltwater upconing in relatively deep wells or by the concentration of pumping.