bluuebunny/crossref_metadata_2025 huggingface dataset:
Empirical‐statistical downscaling in climate modeling
Authors: Benestad R. E.
Published: October 2006

Research into possible impacts of a climate change requires descriptions of local and regional climate. For instance, the local and regional aspect of a climate change is stressed in the U.S. Strategic Plan for the Climate Change Science Program (CCSP) (http://www.climate‐science.gov/Library/stratplan2003/default.htm). Global climate models (GCMs) are important tools for studying climate change and making projections for the future. Although GCMs provide realistic representations of large‐scale aspects of climate, they generally do not give good descriptions of the local and regional scales. It is nevertheless possible to relate large‐scale climatic features to smaller spatial scales.
Intra‐Oceanic Subduction Systems:Tectonic and Magmatic Processes
Authors: Fischer Tobias
Published: October 2006

Subduction zones are locations where oceanic lithosphere, capped with altered crust and sediments, is recycled into Earth's interior. Dehydration of the subducted slab causes the generation of arc magmas with unique geochemical characteristics.

The total length of active margins is about 43,500 km, and most of this length is situated on continental crust and marked by spectacular volcanoes as in the Andes and Japan. Some 17,000 km (∼40%) of volcanic arcs, are situated on oceanic crust. These intra‐oceanic arcs are much less studied than their continental counterparts. The reason is that they are located in some of the world's most remote regions and their volcanoes are typically submerged below sea level. Because intra‐oceanic arcs are situated on thin, mafic oceanic crust, contamination of magmas by high silica crust normally does not occur, allowing for a more straight forward investigation of mantle processes than in continental arcs. Intra‐oceanic arcs are also thought to represent locations where basaltic crust is modified to form continental crust, a still poorly understood process.
ASTER views a high altitude Tibetan Lake in stereo
Authors: Matthews J. P. , Wallis S. R. , Yamaguchi Y.
Published: October 2006

The lakes of the Tibetan Plateau (Figure 1) have been investigated by Western and Chinese scientists over many years [e.g., Gasse et al, 1991;Zheng, 1997]. They are often located in extremely remote and inhospitable terrain at altitudes above 4000 m and, as a result, boat‐based research campaigns aimed toward an improved understanding of the limnology and limnogeology of these water bodies are time consuming and difficult to perform.

In order to support recent field studies of the Tibetan lakes, high spatial resolution imagery acquired by ASTER (the Advanced Spaceborne Thermal Emission and Reflection Radiometer) has been used.These data were gathered in the visible, near‐infrared, and thermal infrared bands as ASTER operated on the TERRA platform [Yamaguchi et al, 1998], a component of NASAs Earth Observing System (EOS).The research outlined here has benefited, in particular, from the availability of stereo data gathered by ASTER, in which regions are imaged first at nadir and then from a backward looking slant view some 55 s later in the near‐infrared (channel 3B, 0.781–0.86 µm).
The role of paleoclimatic studies in assessing climate change
Authors: Thompson Robert S.
Published: October 2006

As the international community ponders the potential course of future climatic changes and their impacts, studies of past climatic changes and their environmental effects provide a way to understand the processes involved in environmental change, the interactions among elements of the ocean‐atmosphere‐land surface system, and the rates and amplitudes of natural climatic variability.

Paleoclimatic studies provide direct evidence of how the climate system changes through time, including its responses to unprecedented (in the instrumental record) changes in its controls.The paleoclimatic record also provides a laboratory for testing the ability of numerical models to simulate conditions different from the current climate.
Exploiting MODIS data for estimating sea surface nitrate from space
Authors: Goes Joaquim I. , Gomes Helga do R. , Saino T. , Wong C. S. , Mordy C. W.
Published: October 2006

A better understanding of the oceans' carbon cycle and a reduction in existing uncertainties in estimates of CO2 fluxes between the atmosphere and the oceans have become central to several contemporary programs. Oceanic CO2 fluxes are largely regulated by the “solubility pump” and the "biological pump." The solubility pump is governed by physical processes that include near‐surface conditions at the air‐sea interface, the partial pressure of CO2 between the sea surface and the atmosphere, and the solubility of CO2 in seawater.

The biological pump, in turn, is regulated by phytoplankton photosynthesis, which converts CO2 to organic matter. The fraction of newly photosynthesized carbon exported to depth in the oceans is referred to as “export production” or “new production,” and is largely dependent on exogenous nitrogeneous nutrient inputs, primarily nitrate into the euphotic zone [Eppley and Peterson, 1979].
MODIS detects a devastating algal bloom in Paracas Bay, Peru
Authors: Kahru Mati , Michell B. Greg , Diaz Anibal , Miura Manuel
Published: October 2006

The medium‐resolution bands on NASA's Moderate‐Resolution Imaging Spectroradiometer (MODIS) were successfully used to detect and map the distribution of a harmful phyto‐plankton bloom in the Paracas Bay Peru, that caused economic losses worth millions of dollars. Routine application of MODIS data can be a valuable and cost‐effective way to monitor harmful blooms and other turbid water plumes that cause disruption to the fishery and aquaculture operations of many coastal areas.
Future applications of thorium‐234 in aquatic ecosystems
Authors: Benitez‐Nelson Claudia ,   The th‐Group
Published: October 2006

A fundamental and outstanding issue in marine biogeochemistry is understanding the mechanisms that control and enhance the flux of material from the surface ocean to depth. “Sinking particles” are the ultimate removal mechanism of many biologically and particle reactive elements from the ocean. This includes atmospheric carbon, which is converted from CO2 to particulate phases during biological production and sequestered to deep waters via particle sinking. Unfortunately the temporal and spatial magnitude of the sinking particle flux remains an elusive and difficult process to study.
A magmatic mush column rosetta stone: The McMurdo Dry Valleys of Antarctica
Authors: Marsh Bruce
Published: October 2006

A long‐running mystery of Earth science concerns the physical and dynamic connection between volcanism, plutonism, magma chambers, layered intrusions, and the production from mantle material of oceanic and continental crust. The basic chemical connection of fractionating melt from crystals and resorting crystals again and again is clear, but volcanologists and plutonists covet almost mutually exclusive, process‐oriented sciences to explain the compositional sequences and textures found in stacks of lavas and expanses of plutons.

Lavas present an extensive time series of quenched aliquots of magma without any clear measure of the evolutionary spatial context of sampling within the magmatic system. Plutons offer extensive spatial context without a clear physical connection to the greater active magmatic system and without a sequential capturing of time; critical original textural details are erased under long cooldown times. A deadly middle ground must be crossed to meld the timescales and textures captured by volcanism with the spatial scales and textural processes of plutonism into a conceptual representation of an integrated working magmatic system.
Humans transforming the global water system
Authors: Vörösmarty C. , Lettenmaier D. , Leveque C. , Meybeck M. , Pahl‐Wostl C. , Alcamo J. , Cosgrove W. , Grassl H. , Hoff H. , Kabat P. , Lansigan F. , Lawford R. , Naiman R.
Published: October 2006

Fresh water figures prominently in the machinery of the Earth system and is key to understanding the full scope of global change. Greenhouse warming with a potentially accelerated hydrologic cycle is already a well‐articulated science issue, with strong policy implications. A broad array of other anthropogenic factors—widespread land cover change, engineering of river channels, irrigation and other consumptive losses, aquatic habitat disappearance, and pollution—also influences the water system in direct and important ways. A rich history of site‐specific research demonstrates the clear impact of such factors on local environments. Evidence now shows that humans are rapidly intervening in the basic character of the water cycle over much broader domains. The collective significance of these many transformations on both the Earth system and human society remains fundamentally unknown [Framing Committee of the GWSP, 2004].
Quantifying mineral dust mass budgets:Terminology, constraints, and current estimates
Authors: Zender C. S. , Miller R. L.R. L. , Tegen I.
Published: October 2006

Mineral dust aerosol is created by wind erosion of soil particles. In addition to its direct radiative effect, dust aerosol mediates ocean carbon uptake and the chemical cycles of other aerosols like sulfates. Dust observations during the past decade span measurements of local concentration and deposition to global satellite retrievals of aerosol optical thickness [Prospero et al., 2002].

Measurements of dust emission, whereby soil particles enter the atmosphere, are scarce. Because no single data set is sufficient to constrain the three‐dimensional distribution of dust aerosol and its evolution with time, the dust cycle is currently estimated using models that are constrained by available measurements and retrievals.
Comment [on “Cosmic rays, carbon dioxide, and climate”]
Authors: Shaviv Nir , Veizer Jan , Veizer Jan
Published: October 2006

Rahmstorf et al. [2004], in their “critique” of Shaviv and Veizer [2003], assert that the proposed correlation between cosmic ray flux (CRF) and paleoclimate during the Phanerozoic does not “hold up under scrutiny” because its astrophysical background is based on “questionable assumptions” and circular reasoning, and because the meteoritic and terrestrial databases and statistics are manipulated.

They further claim that the Shaviv and Veizer [2003] treatment of the CO2/climate relationship is not scientifically sustainable, and that the oxygen isotope record is likely a proxy of oceanic pH and not of paleotemperature. They make a host of additional assertions that cannot all be restated here.
Measuring the Oceans From Space
Authors: Martin Seelye
Published: October 2006

Given the growth in the number and complexity of ocean satellite systems since the launch of Seasat in 1978, combined with the fact that about twenty‐five countries are now involved in such observations, this is an appropriate time for a new book on satellite oceanography (Disclosure: the book reviewer has also just published an ocean remote sensing book.). The present book is an expanded version of Robinson's 1985 book, Satellite Oceanography.

It consists of two parts: fundamentals of satellite oceanography and remote sensing techniques. Although Robinson originally planned to include a third part on ocean applications, because of the length of the current book, that section will be published separately in 2005. The present book discusses for the ice‐free ocean “what is measured and how it is done.”
The “road to the MoHole” four decades on: Deep drilling at Site 1256
Authors: Tagle Damon A. H. , Wilson Douglas S. ,   ODP Leg 206 Shipboard Party, Acton Gary D.
Published: October 2006

Ocean Drilling Program (ODP) Hole 1256D, drilled 500 m into oceanic basement in the Guatemala Basin, is the first hole prepared with the infrastructure desirable for drilling a moderately deep hole into the oceanic basement (1.5–2 km). A second ocean drilling leg to this site should finish the recovery of the first complete section of upper oceanic crust from lavas down through the dikes into the upper‐most gabbros. Although Site 1256 has many advantageous features for a program to drill to the mantle, planning such an operation now would be premature, due in part to lack of engineering experience. In addition, there is significant scientific knowledge to be gained from drilling to depths of 1–3 km. Only through the characterization of the heterogeneity of the ocean crust by moderate‐depth drilling at this and other sites will the essential information necessary to even choose a location for a full crustal penetration be acquired. The information learned on the “road to” selecting a MoHole site is at least as important as succeeding with that inspirational goal itself [see also Murray et al, 2002].
Global sawtooth oscillations of the magnetosphere
Authors: Borovsky Joe
Published: October 2006

Global sawtooth oscillations are periodic changes in the morphology of the magnetosphere wherein the magnetic field in the inner regions strongly stretches and then rapidly crashes or dipolarizes. The period of the oscillation is about three hours, with the crash phase lasting 5–15 min. At geosynchronous orbit, a sawtooth oscillation of the magnetosphere appears as a periodic decline and rapid recovery of the energetic particle fluxes at all local times; such an oscillation is shown in Figure 1.

Global sawtooth oscillations occur during some, but not all, geomagnetic storms. Owing to the extremely large amplitudes of the sawtooth oscillations, nearly all measurements taken in the magnetosphere show signatures of the sawtooth oscillations.
Is there a mantle plume below Italy?
Authors: Bell Keith , Castorina Francesca , Lavecchia Giusy , Rosatelli Gianluigi , Stoppa Francesco
Published: October 2006

Some of the most diverse igneous rocks found on Earth occur along the length of Italy and in many of the islands in the southeastern Tyrrhenian Sea, all the result of Cenozoic magmatism. Magmas extremely rich in alkalis, particularly potassium, and many undersaturated with respect to silica, were erupted, as well as others of calc‐alkalic affinity (see legend in Figure 1).

Their origin has been the subject of heated debate, and there is still no general consensus about how they formed. Most attribute them to subduction‐related processes (see Beccaluva et al. [2004] for a review); others consider them to be the result of within‐plate magmatism [e.g., Vollmer, 1976; Lauecchia and Stoppa, 1996]. Still others consider magmatism the result of a deep, mantle upwelling within a slab window coupled with mixing between isotopically different reservoirs [Gasperini et al., 2002].
Hydrate‐bearing structures in the Sea of Okhotsk
Authors: Shoji Hitoshi , Minami Hirotsugu , Hachikubo Akihiro , Sakagami Hirotoshi , Hyakutake Kinji , Soloviev Valery , Matveeva Tatiana , Mazurenko Leonid , Kaulio Vitaly , Gladysch Vyacheslav , Logvina Elizaveta , Obzhirov Anatoly , Baranov Boris , Khlystov Oleg , Biebow Nicole , Poort Jeffrey , Jin Young Keun , Kim Yeadong
Published: October 2006

Gas hydrates are natural gas reservoirs in ice‐like crystalline solids, and are stable in pore spaces of submarine sediments in water depths greater than about 300–500 m. They have been recovered in many of the world's oceans, both at larger sub‐bottom depths (up to 450 m) by drilling and near the seafloor in shallow cores by gravity‐coring. In the latter case, the gas hydrates are related to the sites of enhanced seepage such as cold seeps and mud volcanoes [Ginsburg and Soloviev, 1998].

Multidisciplinary field investigations during the two cruises have revealed new, large hydrate‐bearing seepage structures in the Sea of Okhotsk, a northwestern marginal sea of the Pacific Ocean (Figure l). The Derugin Basin at the central part of the Sea of Okhotsk, the zone of intensive gas seepage and hydrate accumulation, was studied during two cruises of the R/V Akademik M.A. Lavrentyev (LV) of the Russian Academy of Sciences (RAS), in August and October 2003 within the framework of the CHAOS project (hydroCarbon Hydrate Accumulations in the Okhotsk Sea) supported by funding agencies in five nations.
Where rivers and oceans collide
Authors: Crockett J. S. , Nittrouer C. A. , Ogston A. S. , Sternberg R. W. , Driscoll N. W. , Babcock J. , Milliman J. D. , Slingerland R. , Naar D. F. , Donahue B. , Walsh J. P. , Dietrich W. , Parker G. , Bera M. , Davies H. , Harris P. , Goni M. , Aller R. , Aller J.
Published: October 2006

Fluvial sediment fills the coastal ocean, and sea level rise floods river valleys. This epic battle of terrestrial and marine processes occurs along all shorelines, and the complexities are especially well revealed in the Gulf of Papua, a foreland basin on the southern coast of New Guinea. Two hundred to four hundred million tons of sediment are supplied each year by the Fly and other rivers to a continental shelf that has been dissected by ancestors of these same rivers. The new sediment builds a large depositional feature known as a clinoform, which grows seaward and buries the record of earlier environments.
Living With Earthquakes in the Pacific Northwest: A Survivor's Guide, 2nd edition
Authors: Hutton Kate
Published: October 2006

In 1995, Robert S.Yeats found himself teaching a core curriculum class at Oregon State University for undergraduate nonscience majors, linking recent discoveries on the earthquake hazard in the Pacific Northwest to societal response to those hazards. The notes for that course evolved into the first edition of this book, published in 1998. In 2001, he published a similar book, Living With Earthquakes in California: A Survivors Guide (Oregon State University Press).

Recent earthquakes, such as the 2001 Nisqually Mw6.8, discoveries, and new techniques in paleoseismology plus changes in public policy decisions, quickly outdated the first Pacific Northwest edition. This is especially true with the Cascadia Subduction Zone and crustal faults, where our knowledge expands with every scientific meeting.
Unveiling the mystery of North Pacific intermediate water formation
Authors: You Yuzhu
Published: October 2006

How were the sources of the subtropical North Pacific Intermediate Water (NPIW), which has a core density of 26.8σθ formed in the subpolar region, given that the maximum surface density in the late winter (density reaches a maximum in March due to successive cooling through the winter) of the entire North Pacific is only 26.5σθ? How, then, did these sources cross the broad subarctic‐tropical frontal zone (SATFZ) (which is about 800 km in width and has predominantly eastward flowing currents) and enter the subtropical gyre southward, forming the NPIW? These questions have been addressed recently. This article provides an update.

The previously conjectured pathway (a path of NPIW's source water en route to the subtropical gyre from the formation region, the Okhotsk Sea) was a shortcut directly from the western subpolar gyre into the subtropical gyre. Such a pathway required an isopycnal (along a constant density surface) salinity minimum that is not found immediately south of the SATFZ in the northwestern subtropical gyre.
Graphical user interface for interactive seismic ray tracing
Authors: Song Jianli , Brink Uri Ten
Published: October 2006

RayGUI 2.0 is a new version of RayGUI,a graphical user interface (GUI) to the seismic travel time modeling program of Zelt and Smith [1992]. It represents a significant improvement over the previous version of RayGUI (RayGUI 1.04; Loss et al. [1998a, 1998b]).

RayGUI 2.0 uses an updated Java version (1.3), and can run on various operating systems (UNIX, Linux, and Mac OS X). Several new functions have been incorporated, including executing the forward and inversion codes of Zelt and Smith [1992], creating models or adding new parts of models from an ASCII file, graphically adding layers or points, graphically pinching layers, changing the velocity value of a control point, reporting point location and velocity importing travel‐time lists, generating postscript files, exporting the velocity model into an ASCII file, generating 1‐D velocity profiles at specified locations, calculating rootmean‐square errors between observed and calculated arrivals for selected phases, and accessing the ray trace log, as well as several other new display features.
Landslide surveillance: New tools for an old problem
Authors: Chadwick J. , Thackray G. , Dorsch S. , Glenn N.
Published: October 2006

Landslides are one of the most widespread geological hazards on Earth, responsible for hundreds of deaths and billions of dollars in property damage per year. Landslides commonly occur with other natural disasters (e.g., earthquakes, floods) and leave the landscape prone to sedimentation, erosion, and further mass wasting.

Remote sensing, the Global Positioning System (GPS),and geographic information systems (GIS) are now mature technologies that can be used to monitor landslides and landslideprone areas with greater accuracy than could be accomplished previously with field reconnaissance alone.
Impact of atmospheric infrared sounder observations on weather forecasts
Authors: Le Marshall J. , Jung J. , Derber J. , Treadon R. , Lord S. J. , Goldberg M. , Wolf W. , Liu H. C. , Joiner J. , Woollen J. , Todling R. , Gelaro R.
Published: October 2006

Experimental weather forecasts at the Joint Center for Satellite Data Assimilation (JCSDA) using Atmospheric Infrared Sounder (AIRS) radiance observations indicate significant improvements in global forecast skill compared with the operational system without AIRS data. The improvement in forecast skill at six days is equivalent to gaining an extension of forecast capability of several hours.

This magnitude of improvement is quite significant when compared with the rate of general forecast improvement over the last decade. A several hour increase in forecast range at five or six days normally takes several years to achieve at operational weather centers.
Preparedness and mitigation systems for Asian tsunami‐type hazards
Authors: Aswathanarayana U.
Published: October 2006

The devastating impact of the 26 December 2004 Indian Ocean tsunami (also known as the Asian tsunami) on coastal communities has been widely reported in the media. The tsunami has so traumatized the public that governments are under pressure to spend vast amounts of money for warning and protective measures against the tsunamis. It should not, however, be forgotten that tsunamis are comparatively rare events, and consequently the expenditure on preparedness should be commensurate with the probability of risk.

It is safe to state that the probability of an equally powerful tsunami being triggered at around the same location in the next few decades is low (http://www.msnbc.msn.com/id/6759529/site/newsweek/), for two reasons: (1) The repeat time for Sumatran‐type subduction zone earthquakes is typically 200–300 years; and (2) the tsunami of 26 December was rendered so powerful because of the sudden release of the stress energy that accumulated over a long period of time in the area. This does not, however, preclude less powerful tsunamis from being set off in the future at this or other locations in the Sumatran belt.
Linking the scales of observation, process, and modeling of dust emissions
Authors: Kohfeld K. E. , Reynolds R. L. , Pelletier J. D. , Nickling B.
Published: October 2006

Each year, approximately four billion tons of dust are mobilized from dry landscapes and remain in the atmosphere from hours to weeks before being deposited. These large atmospheric dust loadings directly affect atmospheric dynamics and global climate [Intergovernmental Panel on Climate Change, 2001], human health [Plumlee and Ziegler, 2003], and soil fertility, and also influence ecosystem dynamics in ocean basins.

Although some progress has been made in quantifying feedbacks (see Figure 1 on the Eos Electronic Supplement at http:www. agu. org/eos_elec/000931e.html) in the atmospheric dust cycle, the critical factors controlling the entrainment and transport of dust at differing spatial and temporal scales remain poorly quantified.
High risk of tsunami in the northern Caribbean
Authors: Grindlay Nancy R. , Hearne Meghan , Mann Paul
Published: October 2006

The magnitude Mw = 9.3 Sumatra earthquake of 26 December 2004 claimed the lives of an estimated 300,000 people living in coastal areas of seven different countries around the Indian Ocean. This event raised the question of whether similar far‐traveled tsunamis generated by plate boundary faulting could affect the estimated 150 million people living in coastal areas of the United States, including Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands.

Aside from the Pacific plate margin of North America, the North America‐Caribbean plate boundary is the closest (∼2000 km) active plate boundary to coastal areas in the Gulf of Mexico and the U.S. Atlantic seaboard. Researchers also have proposed that other possible tsunami‐generating sources that could affect coastal areas of the United States include slumping of the shelf margin along the Virginia‐North Carolina margin [Driscoll et al., 2000] and slumping of volcanic edifices in the Canary Islands [Ward and Day, 2001].
Northern Adriatic response to a wintertime bora wind event
Authors: Lee Craig M. , Askari Farid , Book Jeff , Carniel Sandro , Cushman‐Roisin Benoit , Dorman Clive , Doyle James , Flament Pierre , Harris Courtney K. , Jones Burton H. , Kuzmic Milivoj , Martin Paul , Ogston Andrea , Orlic Mirko , Perkins Henry , Poulain Pierre‐Marie , Pullen Julie , Russo Aniello , Sherwood Christopher , Signell Richard P. , Thaler Dietmar
Published: October 2006

During winters, the northern Adriatic Sea experiences frequent, intense cold‐air outbreaks that drive oceanic heat loss and imprint complex but predictable patterns in the underlying waters. This strong, reliable forcing makes this region an excellent laboratory for observational and numerical investigations of air‐sea interaction, sediment and biological transport, and mesoscale wind‐driven flow.

Narrow sea surface wind jets, commonly known as “bora,” occur when cold, dry air spills through gaps in the Dinaric Alps (the mountain range situated along the Adriatic's eastern shore). Horizontal variations in these winds drive a mosaic of oceanic cyclonic and anticyclonic cells that draw coastal waters far into the middle basin. The winds also drive intense cooling and overturning, producing a sharp front between dense, vertically homogenous waters (North Adriatic Dense Water, or NAdDW) in the north and the lighter (colder, fresher), stratified waters of the Po River plume. Once subducted at the front, the NAdDW flows southward in a narrow vein following the isobaths (contours of constant depth) of the Italian coast. In addition to governing the basin's general circulation, these processes also influence sediment transport and modulate biological and optical variability
Three‐dimensional model for the crust and upper mantle in the Barents Sea region
Authors: Bungum H. , Ritzman O. , Maercklin N. , Faleide J.‐I. , Mooney W. D. , Detweiler S. T.
Published: October 2006

The Barents Sea and its surroundings is an epicontinental region which previously has been difficult to access, partly because of its remote Arctic location (Figure 1) and partly because the region has been politically sensitive. Now, however, this region, and in particular its western parts, has been very well surveyed with a variety of geophysical studies, motivated in part by exploration for hydrocarbon resources. Since this region is interesting geophysically as well as for seismic verification, a major study [Bungum et al., 2004] was initiated in 2003 to develop a three‐dimensional (3‐D) seismic velocity model for the crust and upper mantle, using a grid density of 50 km.

This study, in cooperation between NORSAR, the University of Oslo (UiO),and the U.S.Geological Survey (USGS), has led to the construction of a higher‐resolution, regional lithospheric model based on a comprehensive compilation of available seismological and geophysical data. Following the methodology employed in making the global crustal model CRUST5.1 [Mooney et al., 1998], the new model consists of five crustal layers: soft and hard sediments, and crystalline upper, middle, and lower crust. Both P‐ and S‐wave velocities and densities are specified in each layer. In addition, the density and seismic velocity structure of the uppermost mantle, essential for Pn and Sn travel time modeling, are included.
IRIS Seismology Program marks 20 years of discovery
Authors: Aster R. , Beaudoin B. , Hole J. , Fouch M. , Fowler J. , James D.
Published: October 2006

The year 2004 marked the twentieth anniversary of the Incorporated Research Institutions for Seismology (IRIS) Consortium and its four core programs: the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL), the Global Seismic Network (GSN), Education and Outreach (E&O),and the Data Management System (DMS).

IRIS activities (www.iris.edu) are supported principally through the U.S. National Science Foundation's (NSF) Earth Sciences Instrumentation and Facilities Program, and through the community efforts of IRIS's more than 150 member institutions in the United States and abroad. The consortium provides fundamental capabilities for the exploration of the Earth's interior through the collection and distribution of seismographic data. PASSCAL is the IRIS facility program dedicated to seismographic data collection associated with temporary deployments using highly portable instrumentation.
Global‐scale drought caused atmospheric CO2 increase
Authors: Knorr Wolfgang , Scholze Marko , Gobron Nadine , Pinty Bernard , Kaminski Thomas
Published: October 2006

Identifying the mechanisms driving interannual fluctuations of atmospheric carbon dioxide is necessary for predicting future CO2 concentrations and climate change [Prentice et al., 2001]. A possible clue comes from a well‐established positive correlation between atmospheric CO2 growth rates and the El Niño‐Southern Oscillation phenomenon [Keeling et al., 1989; Bousquet et al., 2000]. Most tropical droughts are also linked to El Niño [Lyon, 2004], suggesting carbon losses from drought as a major cause for interannual CO2 variations.

A lag correlation between 7‐month running means (see Figure 1) of monthly atmospheric CO2 concentrations [Cooperative Atmospheric Data Integration Project, 2004] and Niño 3 sea surface temperatures (available at http://www.cpc.noaa.gov/data/indices/) for the period 1979–2003 peaks at a lag of four months with a correlation of 0.49, and a significance level above 99.9% (assuming 42 independent measurements).
A strategy to rapidly determine the magnitude of great earthquakes
Authors: Menke William , Levin Vadim
Published: October 2006

In the initial hours following the origin of the Sumatra‐Andaman Islands earthquake at 0058:53 GMT on 26 December 2004, the event was widely reported as having a magnitude of about 8. Thus, its potential for generating a damaging teletsunami (ocean‐crossing tsunami) was considered minimal.

The event's size later was shown to be approximately 10 times larger, but only after more than four and a half hours had passed, when a moment estimate based on 2.5 hours of data became available from Harvard University's Centroid‐Moment Tensor (CMT) Project (M.Netties and G. Ekstrom, Quick CMT of the 2004 Sumatra‐Andaman Islands earthquake, Seismoware FID: BR345, e‐mailed announcement, 26 December 2004). This estimate placed its magnitude at Mw ≈9.0, in the range capable of generating a damaging teletsunami. Actually, the earthquake had caused a teletsunami, one that by that time had already killed more than a hundred thousand people. The magnitude estimate has been subsequently revised to at least 9.3 (Stein and Okal, http://www.earth.northwestern.edu/people/∼seth/research/sumatra.html), with the exact magnitude of the event likely to be a subject of further research in the coming years.
Exploring subglacial Antarctic lake environments
Authors: Priscu J. C. , Kennicutt M. C. , Bell R. E. , Bulat S. A. , Ellis‐Evans J. C. , Lukin V. V. , Petit J.‐R. , Powell R. D. , Siegert M. J. , Tabacco I.
Published: October 2006

While subglacial lakes have been suspected, and speculated about, for more than 50 years, recent analyses of historical and new data have shown that liquid water environments are common beneath the vast Antarctic Ice Sheet. Airborne radar surveys have now documented more than 145 subglacial lakes, the largest being Lake Vostok located 4 km beneath the vast East Antarctic Ice Sheet (Figure 1).

The public and scientists alike have been intrigued by the possibility that these environments harbor life in conditions not previously studied on our planet. Planning for the exploration and study of these unique environments has focused international attention on the challenges presented by the way science is conducted in such settings while providing for environmental protection and stewardship. Exploration of subglacial environments will require careful and detailed planning, adoption of environmental protocols, and international cooperation.
Remotely monitoring volcanic activity with ground‐based Doppler radar
Authors: Donnadieu F. , Dubosclard G. , Cordesses R. , Druitt T. , Hervier C. , Kornprobst J. , Lénat J.‐F. , Allard P. , Coltelli Mauro
Published: October 2006

Concern about hazards that volcanic plumes pose, especially to aviation safety, has led scientists for about two decades to use satellite sensors in different wavelengths for the detection and study of volcanic activity. Together with ground‐based meteorological radars, these techniques now enable tracking the ascent and dispersal of large eruptive clouds, making reflectivity mapping, determining plume heights, measuring gas (SO2) and aerosols content, and estimating particle sizes and total mass of gas and fine ash [e.g., Harris and Rose, 1983].

However, there is still a crucial need for direct measurements of particle velocities, especially near an emission vent, to constrain physical and numerical models of eruption dynamics, which in turn should improve our predictive capacity regarding plume behavior.
Hydrothermal and volcanic activity found on the Southern Mid‐Atlantic Ridge
Authors: Devey C. W. , Lackschewitz K. S. , Baker E.
Published: October 2006

The process of plate accretion at mid‐ocean ridges, once thought to occur in a relatively simple, magmatic system, has been shown in recent years to possess unexpected layers of complexity [e.g., Cannat, 1996; Escartín and Lin, 1998; Jokat et al., 2003; Michael et al., 2003]. Particularly at lower spreading rates, the magma supply to some or all of the ridge decreases, with the plate spreading motion being taken up instead on faults.

The balance between these magmatic and tectonic processes governs such features as the topography, seismic activity location of hydrothermal vents, and degree of chemical exchange between crust and ocean at spreading axes. It therefore has important implications for the hydrothermal marine biosphere and global chemical budgets.
Airborne laser scanning for high‐resolution mapping of Antarctica
Authors: Csatho Bea , Schenk Toni , Krabill William , Wilson Terry , Lyons William , McKenzie Garry , Hallam Cheryl , Manizade Serdar , Paulsen Timothy
Published: October 2006

In order to evaluate the potential of airborne laser scanning for topographic mapping in Antarctica and to establish calibration/validation sites for NASA's Ice, Cloud and land Elevation Satellite (ICESat) altimeter mission, NASA, the U.S. National Science Foundation (NSF), and the U.S. Geological Survey (USGS) joined forces to collect high‐resolution airborne laser scanning data.

In a two‐week campaign during the 2001–2002 austral summer, NASA's Airborne Topographic Mapper (ATM) system was used to collect data over several sites in the McMurdo Sound area of Antarctica (Figure 1a). From the recorded signals, NASA computed laser points and The Ohio State University (OSU) completed the elaborate computation/verification of high‐resolution Digital Elevation Models (DEMs) in 2003. This article reports about the DEM generation and some exemplary results from scientists using the geomorphologic information from the DEMs during the 2003–2004 field season.
Hydrologic ensemble prediction experiment focuses on reliable forecasts
Authors: Franz Kristie , Ajami Newsha , Schaake John , Buizza Roberto
Published: October 2006

The Hydrologic Ensemble Prediction Experiment (HEPEX), an effort involving meteorological and hydrological scientists from research, operational, and user communities around the globe, is building a research project focused on advancing probabilistic hydrologic forecasting.

HEPEX was launched in March 2004 at a meeting hosted by the European Centre for Medium‐Range Weather Forecasts (ECMWF), in Reading, United Kingdom http://www.ecmwf.int/newsevents/meetings/workshops/2004/HEPEX/). The goal of HEPEX is “to bring the international hydrological and meteorological communities together to demonstrate how to produce reliable hydrological ensemble forecasts that can be used with confidence by the emergency management and water resources sectors to make decisions that have important consequences for the economy, public health, and safety.”
[Comment on “Speaking up for science” by Fred Spilhaus] Science in Plain English
Authors: Sorensen Sorena Svea
Published: October 2006

I write inspired by Fred Spilhaus's Eos editorial (Speaking Up For Science, 86(24), 14 June 2005, p. 225). I have recently had a front‐row seat (at the National Museum of Natural History, Smithsonian Institution) from which to observe the skillful packaging and energetic marketing of a fundamentally religious view of cosmology as science. (Yes, I have seen the film The Privileged Planet.) However, my subject is communication, and what follows is my personal opinion.

I confess: I have many times crossed out the word “believe” in a scientific manuscript and noted, “Science is not a belief system.” I hope my victim will become just angry enough with me to remember in the future that a scientist may “conclude” anything the data support but not “believe” it. Why? “Believing” something can mean that one has a firm religious faith in it. This makes the scientist vulnerable to those who wish to define “materialistic science” as a religious belief, and thus aids advocates of alternate “theories” to those of modern evolutionary biology.
A challenge to the membership
Authors: Austin James A. , Manduca Cathy
Published: October 2006

Students are key to the future of the Earth and space sciences and to the vitality of our global AGU community. More than 7300 students are now members of the Union (17% of the total membership); of these, 30% live outside the U.S. Equally important, student attendance at AGU's major meetings has been steadily climbing. In 2004, a remarkable 25% of the registrants for major AGU meetings were students.

An increasing number of qualified students apply for travel grants to attend these meetings. Yet, only 5% (see Figure 1) receive these modest grants of $300–$650 because Union resources have not kept pace with demand. More students need financial aid, and our charge is to “find” the funds to help them.
Collecting, digitizing, and distributing historical seismological data
Authors: Michelini Alberto , De Simoni Bruno , Amato Alessandro , Boschi Enzo
Published: October 2006

The digital preservation of the unique seismological heritage consisting of historical seismograms and earthquake bulletins, and of related documentation (e.g., observatory logbooks, station books, etc.), is critically important in order to avoid deterioration and loss overtime [Kanamori, 1988]. Dissemination of this seismological material in digital form is of equal importance, to allow reanalysis of past earthquakes using modern techniques and the reevaluation of seismic hazard. This is of particular interest for those areas where little or no earthquake activity has occurred since the last significant historical earthquake.

In 2001, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) started an innovative project, Progetto SISMOS (i.e., SISMOgrammi Storici), to scan (i.e., convert into digital form for storage on a computer), at very high resolution,and archive seismological paper records and related material. The Italian Ministry for the Environment originally funded the project to encompass the digitization of seismogram records of the Italian seismic observatories and of associated bulletins
A chemotrophic ecosystem found beneath Antarctic Ice Shelf
Authors: Domack Eugene , Ishman Scott , Leventer Amy , Sylva Sean , Willmott Veronica , Huber Bruce
Published: October 2006

A new habitat for chemotrophic ecosystems has been found beneath the former extent of the Larsen Ice Shelf in Antarctica. This is the first report of such ecosystems in the Antarctic. (Chemotrophic ecosystems derive their primary metabolic energy from chemical reactions other than those of photosynthetic origin.)

An association of microbial mats and cold seep clam communities, is described, that thrived within an 850‐m‐deep glacial trough some 100 km, or more, from the ice shelf front. However, the continued existence of this unique ecosystem is uncertain, given the increased loading of sediment to the seafloor as a result of the ice shelf's collapse in early 2002. The vent‐related ecology could have a methane source, based upon the vent's similarity with other cold seeps located along continental margins.
Volcanic plume above Mount St. Helens detected with GPS
Authors: Houlié N. , Briole P. , Nercessian A. , Murakami M.
Published: October 2006

Eruptions can produce not only flows of incandescent material along the slopes of a volcano but also ash plumes in the troposphere [Sparks et al., 1997] that can threaten aircraft flying in the vicinity [Fisher et al., 1997]. To protect aircraft, passengers, and crews, the International Civil Aviation Organization and the World Meteorological Organization created eight Volcanic Ash Advisory Centers (VAAC, http://www.ssd.noaa.gov/VAAC/vaac.html) around the globe with the goal of tracking volcanic plumes and releasing eruption alerts to airports, pilots, and companies. Currently, the VAAC monitoring system is based mostly on the monitoring systems of any local volcano observatories and on real‐time monitoring of data acquired by meteorological satellites.
The last word: The definition of halo coronal mass ejections
Authors: Anonymous
Published: October 2006

This is the fifth in a series of essays on terms used in solar‐terrestrial physics that are thought to be in need of clarification. Terms are identified and essays are commissioned by a committee chartered by Division II [Sun and Heliosphere) of the International Astronomical Union. Terminology Committee members include Ed Cliver (chair), Jean‐Louis Bougeret, Hilary Cane, Takeo Kosugi, Sara Martin, Rainer Schwenn, and Lidia van Driel‐Gestelyi. Authors are asked to review the origins of terms and their current usage/misusage. The goals are to inform the community and to promote discussion.

The following article by Chris St. Cyr and colleagues focuses on the term “halo coronal mass ejection (CME).” Halo CMEs are of great interest and import for space weather, but as St. Cyr et al. point out, their definition encompasses various forms of solar eruptive activity, not all of which may affect environmental conditions near Earth. St. Cyr et al. go further and list practical steps being taken to prevent confusion over the use of the term “halo CME” in the future. The community is encouraged to send feedback on this article to the authors, and suggestions for other terms to address in this forum to the IAU Committee.
Global Warming: The Complete Briefing (Third Edition)
Authors: Alverson Keith
Published: October 2006

"What kind of world will our grandchildren inherit?” prods the large, yellow bullet point jumping out from the black background on the back cover of John Houghton's already classic textbook, Global Warming: The Complete Briefing. Students in an undergraduate or first year graduate seminar course—the clear target audience for this book—will come away with little doubt about the answer to this question: a warmer one.

Essentially, this is the Intergovernmental Panel on Climate Change (IPCC) process distilled into a textbook. The first seven chapters, about two thirds of the book's 350 pages, provide a compelling account of the consensus IPCC view of the greenhouse effect, climate variability, climate modeling, climate projections, and the impacts of climate change. These chapters are without doubt the core strength of this excellent textbook, synthesizing an unprecedented two decades of community effort, scientific cooperation, and consensus building into a coherent view.
What is a planet?
Authors: Whithers Paul
Published: October 2006

Atmospheric scientists, forensic scientists, life scientists, neuroscientists, ocean scientists, plant scientists, and almost all other scientists know what lies at the heart of their respective fields, but planetary scientists do not. The last generally accepted definition of a planet, a "wanderer," comes from the ancient Greeks.Although the need for an updated definition has existed since the discovery of the asteroid belt two centuries ago, recent discoveries of objects in the KUiper belt and in orbit around other stars have reminded planetary scientists of this unsatisfactory situation.
Seafloor spreading, sea level, and ocean chemistry changes
Authors: Miller Kenneth G. , Rowley David B. , Kominz Michelle A. , Kent Dennis V.
Published: October 2006

High Cretaceous ocean crust production rates have been causally linked to high global sea level and global CO2 due to increased outgassing. However, recent studies have questioned the empirical basis for high Cretaceous global seafloor spreading rates, high Cretaceous sea level (230–320 m above present), and the relationship between geochemical fluxes and spreading rates.

Although this topic has been discussed at several recent international meetings, there has been little opportunity for the protagonists in the debate of constant versus variable global seafloor spreading rates to interact. However, a group of tectonophysicists, stratigraphers, and geochemists recently met at Rutgers, The State University of New Jersey (Piscataway N.J.) to discuss global seafloor spreading changes and their possible relationships to sea level and geochemical variations.
Mapping deep‐water gas emissions with sidescan sonar
Authors: Klaucke Ingo , Weinrebe Wilhelm , Sahling Heiko , Bohrmann Gerhard , B¨rk Dietmar
Published: October 2006

Emissions of methane gas from cold seeps on the seafloor have a strong impact on a number of biogeochemical processes. These processes include the development of deepsea benthic ecosystems via the process of anaerobic oxidation of methane [Boetius et al., 2000] or the precipitation of carbonates [Ritger et al., 1987]. The fluxes of other chemical species associated with methane emissions may even influence the chemical composition of seawater [Aloisi et al., 2004]. Such gas emissions may have been much more intensive in the past with a strong impact on global climate [Dickens, 1999], as suggested by carbon isotope data.
Tool kit helps digitize tide gauge records
Authors: Ullmann Albin , Pons Frédéric , Moron Vincent
Published: October 2006

The Numerisation des Niveaux d'Eau (NUNIEAU) is an integrated and automated MATLAB computer program tool kit for digitizing, transforming, and validating paper records of sea level variations, called marigrams (Figure 1a), that can cut in half the time required to digitize paper records.

This tool kit developed in 2004 by F. Pons is currently obtainable by request from the developer, but will be available online on the IMPLIT (Impact des evenements extremes sur les hydro‐systèmes du litoral méditerranéen français) Web site in early 2006.