We present a new estimate of the Earth's heat loss based on a new global compilation of heat flow measurements comprising 24,774 observations at 20,201 sites. On a 5 ø x 5 ø grid, the observations cover 62% of the Earth's surface. Empirical estimators, referenced to geological map units and derived from the observations, enable heat flow to be estimated in areas without measurements. Corrections for the effects of hydrothermal circulation in the oceanic crest compensate for the advected heat undetected in measurements of the conductive heat flux. The mean heat flows of continents and oceans are 65 and 101 mW m -2, respectively, which when areally weighted yield a global mean of 87 mW m -2 and a global heat loss of 44.2 x 10 •2 W, an increase of some 4-8% over earlier estimates. More than half of the Earth's heat loss comes from Cenozoic oceanic lithosphere. A spherical hatmonic analysis of the global heat flow field reveals strong sectoral components and lesser zonal strength. The spectrum principally reflects the geographic distribution of the ocean ridge system. The rate at which the heat flow spectrum loses strength with increasing harmonic degree is similar to the decline in spectral strength exhibited by the Earth's topography. The spectra of the gravitational and magnetic fields fall off much more steeply, consistent with field sources in the lower mantle and core, respectively. Families of continental and oceanic conductive geotherms indicate the range of temperatures existing in the lithosphere under various surface heat flow conditions. The heat flow field is very well correlated with the seismic shear wave velocity distribution near the top of the upper mantle.

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Geothermal resources for most European countries are compiled in the recently published Atlas of Geothermal Resources in Europe, a companion volume to the Atlas of Geothermal Resources in the European Community, Austria and Switzerland. Publication of the atlas comes at a time when the promotion of a sustainable and non-polluting energy supply are high on the agenda of local energy suppliers, municipal administrations and all European governments. The participating countries are: Albania,

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fax 01-972-952-9435. AbstractThe need for CO 2 emissions reduction at a large scale globally implies that CO 2 injection into the subsurface be undertaken in a greater variety of geological environments that has been the case previously. Often when the storage reservoirs are saline aquifers, exploration data for proposed injection sites are extremely sparse. The special behaviour of CO 2 -water/brine systems (mutual solubility and chemical reactivity) adds complex processes, such as dry-out, salting-out, chemical reactions to the dynamic model. Simulation in these situations is one of few means of assessing an injection site and testing various scenarios. The accurate description of physics and chemistry in numerical simulation tools is fundamental for understanding processes, as well as designing appropriate injection or mitigation strategies.We present simulations of CO 2 injection into saline aquifers with a fully compositional code that has been expanded and enhanced to include specific phenomena, such as dryingout and salting-out. The examples illustrate the importance of pre-injection studies, as the wrong injection strategy may severely impact injectivity, putting the project in jeopardy.

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We present 56 new heat flow values from the intracratonic Paranti Basin in southern Brazil. This large basin is filled with up to 5 km of Paleozoic and Mesozoic sedimentary rocks. In the Late Jurassic-Early Cretaceous a great igneous event capped most of the basin surface with flood basalts up to 1700 m thick. Geothermal gradients computed from 79 deep exploration boreholes range from 20 K km -1 to 30 K km -1 with the lower gradients generally located in the central part of the basin. Thermal conductivities were determined on 247 core samples. The harmonic mean thermal conductivity of the section encountered by the boreholes decreases from 3.0 W m '1 K -1 at the eastern basin margin to 2.0 W m '1 K '1 in the basin center; this variation is related to the thickening of the basalt cap toward the basin center. Surface heat flow values for the 56 sites range from 40 mW m -2 to 75 mW m '2, with larger and more variable values (50-70 mW m -2) occurring along the eastern margin of the basin in the region without basalt cover. The heat flow in the central part of the basin (40-50 mW m '2) is less than that on the basin margin by about 15 mW m -2 and is more uniform. We discount advective effects as an explanation of the heat flow pattern because if a topographically driven flow system existed, it would diminish heat flow in the elevated recharge area along the basin margin and augment heat flow in the discharge area along the basin axis, opposite to what is observed. Wholly conductive models show that larger-scale thermal conductivity contrasts produced by the flood basalts do not refract significant heat into the surrounding higher-conductivity sedimentary section on the periphery of the basalts. Other model calculations show that the heat flow at the surface reflects the heat input from the basement with only minor, if any, redistribution within the basin. We conclude that the thermal data indicate a dominantly conductive thermal regime within the basin and that the observed heat flow pattern is not likely to result from intrabasinal causes. The observed pattern likely reflects the larger-scale thermal structure of the lithosphere of this region, developed at the time the flood basalts were generate• and extruded.

fax 01-972-952-9435. AbstractThe need for CO 2 emissions reduction at a large scale globally implies that CO 2 injection into the subsurface be undertaken in a greater variety of geological environments that has been the case previously. Often when the storage reservoirs are saline aquifers, exploration data for proposed injection sites are extremely sparse. The special behaviour of CO 2 -water/brine systems (mutual solubility and chemical reactivity) adds complex processes, such as dry-out, salting-out, chemical reactions to the dynamic model. Simulation in these situations is one of few means of assessing an injection site and testing various scenarios. The accurate description of physics and chemistry in numerical simulation tools is fundamental for understanding processes, as well as designing appropriate injection or mitigation strategies.We present simulations of CO 2 injection into saline aquifers with a fully compositional code that has been expanded and enhanced to include specific phenomena, such as dryingout and salting-out. The examples illustrate the importance of pre-injection studies, as the wrong injection strategy may severely impact injectivity, putting the project in jeopardy.