WorldCat Identities

Massachusetts Institute of Technology Department of Earth, Atmospheric, and Planetary Sciences

Overview
Works: 230 works in 237 publications in 1 language and 761 library holdings
Genres: Maps  Conference proceedings  Observations 
Roles: Researcher, Publisher
Classifications: G2801.C72, 551.52460223
Publication Timeline
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Most widely held works about Massachusetts Institute of Technology
 
Most widely held works by Massachusetts Institute of Technology
Plate motions and deformations from geologic and geodetic data semiannual report to the National Aeronautics and Space Administration for the period, 1 August 1984-31 December 1985 by Thomas H Jordan( Book )

2 editions published in 1986 in English and held by 111 WorldCat member libraries worldwide

Lateral variation in upper mantle temperature and composition beneath mid-ocean ridges inferred from shear-wave propagation, geoid, and bathymetry by Anne Frances Sheehan( Book )

1 edition published in 1991 in English and held by 89 WorldCat member libraries worldwide

Mechanisms of interannual ocean-atmosphere interactions final technical report to the National Aeronautics and Space Administration for the grant NAG 5-137 by Claude J Frankignoul( Book )

1 edition published in 1984 in English and held by 55 WorldCat member libraries worldwide

Global ocean surface temperature atlas "Gosta" by M BOTTOMLEY( )

2 editions published in 1990 in English and held by 43 WorldCat member libraries worldwide

Modern methodology in precise engineering and deformation surveys-II : proceedings Deformation Measurements Workshop, Massachusetts Institute of Technology, October 31-November 1, 1986 by Deformation Measurements Workshop( Book )

1 edition published in 1987 in English and held by 15 WorldCat member libraries worldwide

Stochastic modeling of seafloor morphology by John Anson Goff( Book )

1 edition published in 1990 in English and held by 13 WorldCat member libraries worldwide

At scale lengths less than 100 km or so, statistical descriptions of seafloor morphology can be usefully employed to characterize processes which form and reshape abyssal hills, including ridge crest volcanism, off-axis tectonics and volcanism, mass wasting, sedimentation, and post-depositional transport. The objectives of this thesis are threefold: (1) to identify stochastic parameterizations of small-scale topography that are geologically useful, (2) to implement procedures for estimating these parameters from multibeam and side-scan sonar surveys that take into account the finite precision, resolution, and sampling of real data sets, and (3) to apply these techniques to the study of marine geological problems. The seafloor is initially modeled as a stationary, zero-mean, Gaussian random field completely specified by its two-point covariance function. An anisotropic two-point covariance function is introduced that has five free parameters describing the amplitude, orientation, characteristic width and length, and Hausdorff (fractal) dimension of seafloor topography. The general forward problem is then formulated relating this model to the statistics of an ideal multibeam echo sounder, in particular the along-track auto-covariance functions of individual beams and the cross-covariance functions between beams of arbitrary separation. Using these second moments as data functionals, we then pose the inverse problem of estimating the seafloor parameters from realistic, noisy data sets with finite sampling and beamwidth, and we solve this inverse problem by an iterative, linearized, least squares method. Resolution of this algorithm is tested against ship variables such as length of data, the orientation of ship track with respect to topographic grain, and the beamwidth. This analysis is conducted by inverting sets of synthetic data with known statistics. The mean and standard deviation of the inverted parameters can be directly compared with the input parameters and the standard errors output from the inversion. The experiments conducted in this study show that the rms seafloor height can be estimated to within -15% and anisotropic orientation to within ~5* (for a strong lineation) using very short track lengths (down to 3 characteristic lengths, or -10 to 100 km), and characteristic lengths of seafloor topography can be estimated to within -25% using fairly short track lengths (down to 5 or 6 characteristic lengths, or 10's of km to -200 kin). The number of characteristic lengths sampled by a ship track, and hence the accuracy of the estimation, is maximized when the ship track runs perpendicular to abyssal hill lineation. Using the assumed beamwidth, the measured noise values, and the seafloor parameters recovered from the inversion, Sea Beam "synthetics" are generated whose statistical character can be directly compared with raw Sea Beam data. However, these comparisons are spatially limited in the athwart ship direction. A recent SeaMARC II survey along the flanks and crest of the East Pacific Rise between 130 and 15* N included sufficient off-axis topography to permit a comparison of a complete 2-D synthetic topographic field with a region of abyssal-hill terrain that has close to 100% data coverage. Synthetic data is compared to both Sea Beam swaths and SeaMARC II survey data. These comparisons generally indicate that we are successful in characterizing the second order properties of the seafloor. They also indicate the directions we will need to take to improve our modeling, including generalization of the second-order model and characterization of higher moments. The inversion procedure is applied to a data set of 64 near-ridge Sea Beam swaths to characterize near ridge abyssal hill morphology and its relationship to ridge properties. Much of the data (27 swaths) comes from cruises to the Pacific-Cocos spreading section of the East Pacific Rise between 9* and 15* N. These data provide very good abyssal hill coverage of this well-mapped and studied ridge section and form the basis of a regional analysis of the correlation between ridge morphology and stochastic abyssal hill parameters. This regional analysis suggests a strong relationship between magma supply and the character of abyssal hills. We also have data from near the Rivera (9) and Nazca (7) spreading sections of the East Pacific Rise, the Mid-Atlantic Ridge (18), and the Indian- African Ridge (3). Though spotty, this constitutes a good initial data set for the analysis of correlations among covariance parameters and between parameters and ridge characteristics, especially spreading rate. A working hypothesis is introduced to explain the observations within a geological framework. This hypothesis contends 1) that the maximum size of abyssal hills is related to the lithosphere's ability to elastically support the load, 2) that fissuring and horst and graben formation dominate abyssal hill formation at fast spreading ridges, and 3) that volcanic edifice formation, modified by faulting driven by lithospheric necking, dominates abyssal hill formation at slow spreading ridges. To quantify abyssal hill characteristics such as vertical and lateral asymmetry and "peakiness" we must appeal to higher statistical moments than order two. A mathematical framework is introduced for the study of higher moments of a topographic field. This framework is built upon the concept that lower-order moment provide the groundwork for studying the higher-order moments. A simple 1-D parameterized model is proposed for moments up to order 4. This model includes two parameters for the third moment, describing vertical and lateral asymmetries, and one for the fourth moment, which describes the peakiness of topography. Initial methods are developed for estimating these parameters from bathymetric profiles. Results from the near ridge data set are presented and interpreted with regard to abyssal hill forming processes
High sensitivity monitoring of resistivity and self-potential variations in the Palmdale and Hollister areas for earthquake prediction studies : final report by Theodore R Madden( Book )

4 editions published between 1983 and 1986 in English and held by 7 WorldCat member libraries worldwide

Analysis of central California network data for earthquake prediction : final technical report by Keiiti Aki( Book )

2 editions published between 1984 and 1985 in English and held by 5 WorldCat member libraries worldwide

Final report on fault stressing, surface deformation, and gravity anomaly associated with aseismic slilppages [sic] on shallow detachment patches by Victor Li( Book )

1 edition published in 1986 in English and held by 3 WorldCat member libraries worldwide

Evaluating mantle and crustal processes using isotope geochemistry by Alberto Edgardo Saal( Book )

1 edition published in 2000 in English and held by 3 WorldCat member libraries worldwide

Geochemical studies are fundamental for understanding how the dynamic Earth works and evolves. These studies place constraints on the composition, formation, age, distribution, evolution and scales of geochemically distinct reservoirs such as the Earth's crust, mantle and core. In this dissertation the strategy has been to work on a broad range of topics to evaluate crustal and mantle processes. This study presents Re-Os systematics to constrain the composition, formation and age of the lower continental crust and the mantle lithosphere, examines melt inclusion from oceanic island basalts to evaluate the scale of the mantle heterogeneities, and uses U-series isotope to constrain geodynamic parameters, such as the upwelling velocities and porosities of mantle plumes. The lower continental crust plays a pivotal role in understanding the composition and evolution of the continental crust and the petrogenesis of continental basalts. This chapter presents Re/Os isotope measurements which allow us to further our understanding of these problems. Two well-characterized suites of lower crustal xenoliths from Northern Queensland, Australia, which have average major and trace element compositions similar to bulk lower crust, were analyzed for Re/Os isotope systematics. From this data, we infer that the lower crust has 1 to 2 times as much Os, about half of the Re and is less radiogenic in 1870s/1880s than the upper continental crust. Our data show that assimilation and fractional crystallization (AFC) are important processes in the formation of the lower crust and lead to dramatic changes in the Os isotopic composition of basalts that pond and fractionate there. Because of this, the Re-Os system cannot be relied upon to yield accurate mantle extraction ages for continental rocks. Chapter 2 examines the Re-Os isotopic composition of the Horoman massif, Japan. These data indicate that the Os isotope composition is controlled by the Re content, through radiogenic ingrowth, while the Re content is governed by the extent of depletion in "basaltic component" of the ultramafic rocks. Re-Os systematics suggest that depletion model ages of = 1.8 Ga represent the age of the melting event. The colinearity between mafic and ultramafic rocks in the Re-Os isochron diagram defines an apparent age of = 1 Ga. The similar "ages" determined by Re-Os and Sm-Nd isotopes and the high Re/Os ratios in the most fertile peridotites plotting to the right of the geochron, indicate that the mafic layers and the ultramafic rocks are genetically related by a refertilization process which took place = 1 Ga ago. The Re-Os systematics for other ophiolitic massifs indicate that refertilization of the lithospheric mantle seems to be a more widespread process than previously thought. Previous studies have suggested that melting processes are responsible for the trace element variability observed in olivine-hosted basaltic melt inclusions. Melt inclusions from four individual lava samples representing three mantle end-members HIMU, EMI and EMII (two from Mangaia, Cook Islands, one from Pitcairn, Gambier chain, and one from Tahaa, Society chain), have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. The range of Pb isotopic compositions from individual melt inclusions in a single lava flow spans 50% of the world-wide range observed for ocean island basalts (OIB). The melt inclusion data can be explained by two-component mixing for each island. Our data imply that magmas with different isotopic compositions existed in the volcanic plumbing system prior to or during melt aggregation. Evaluation of U-series disequilibrium, trace element composition and He, Sr, Nd and Pb isotopes of Galapagos lavas indicates that magma mixing between plume and asthenospheric melts has been the main process responsible for the geochemical variation observed in the archipelago. Correlations between He isotopes and Ti/Ti*, K/Rb and Nb/La ratios suggest that the mantle plume has positive anomalies of Nb and Ti and negative anomalies of K. 230Th excesses measured in the lavas indicate that the basalts from Galapagos originated completely or partially in the garnet stability field. Mantle upwelling velocity for the Galapagos plume (Fernandina) ranges from= 1 to 3 cm/y with a maximum porosity of 0.3%, indicating that Galapagos is a mildly buoyant plume. Very slow mantle upwelling rates and very low porosity for Pinta (0.5 to 1 cm/y and 0.1%) and Floreana (0.1 cm/year and <0.1%) islands, support the hypothesis that the movement of the plume across the 91050' transform fault into a younger and thinner lithosphere produced slow upwelling and small extents of melting
Adaptive error estimation in linearized ocean general circulation models by Michael Y Chechelnitsky( Book )

1 edition published in 1999 in English and held by 3 WorldCat member libraries worldwide

Data assimilation methods, such as the Kalman filter, are routinely used in oceanography. The statistics of the model and measurement errors need to be specified a priori. In this study we address the problem of estimating model and measurement error statistics from observations. We start by testing the Myers and Tapley (1976, MT) method of adaptive error estimation with low-dimensional models. We then apply the MT method in the North Pacific (5°-60° N, 132°-252° E) to TOPEX/POSEIDON sea level anomaly data, acoustic tomography data from the ATOC project, and the MIT General Circulation Model (GCM). A reduced state linear model that describes large scale internal (baroclinic) error dynamics is used. The MT method, closely related to the maximum likelihood methods of Belanger (1974) and Dee (1995), is shown to be sensitive to the initial guess for the error statistics and the type of observations. It does not provide information about the uncertainty of the estimates nor does it provide information about which structures of the error statistics can be estimated and which cannot. A new off-line approach is developed, the covariance matching approach (CMA), where covariance matrices of model-data residuals are "matched" to their theoretical expectations using familiar least squares methods. This method uses observations directly instead of the innovations sequence and is shown to be related to the MT method and the method of Fu et al. (1993). The CMA is both a powerful diagnostic tool for addressing theoretical questions and an efficient estimator for real data assimilation studies. It can be extended to estimate other statistics of the errors, trends, annual cycles, etc. Twin experiments using the same linearized MIT GCM suggest that altimetric data are ill-suited to the estimation of internal GCM errors, but that such estimates can in theory be obtained using acoustic data. After removal of trends and annual cycles, the low frequency /wavenumber (periods> 2 months, wavelengths> 16°) TOPEX/POSEIDON sea level anomaly is of the order 6 cm2. The GCM explains about 40% of that variance. By covariance matching, it is estimated that 60% of the GCM-TOPEX/POSEIDON residual variance is consistent with the reduced state linear model. The CMA is then applied to TOPEX/POSEIDON sea level anomaly data and a linearization of a global GFDL GCM. The linearization, done in Fukumori et al.(1999), uses two vertical mode, the barotropic and the first baroclinic modes. We show that the CMA method can be used with a global model and a global data set, and that the estimates of the error statistics are robust. We show that the fraction of the GCMTOPEX/ POSEIDON residual variance explained by the model error is larger than that derived in Fukumori et al.(1999) with the method of Fu et al.(1993). Most of the model error is explained by the barotropic mode. However, we find that impact of the change in the error statistics on the data assimilation estimates is very small. This is explained by the large representation error, i.e. the dominance of the mesoscale eddies in the TIP signal, which are not part of the 20 by 10 GCM. Therefore, the impact of the observations on the assimilation is very small even after the adjustment of the error statistics. This work demonstrates that simultaneous estimation of the model and measurement error statistics for data assimilation with global ocean data sets and linearized GCMs is possible. However, the error covariance estimation problem is in general highly underdetermined, much more so than the state estimation problem. In other words there exist a very large number of statistical models that can be made consistent with the available data. Therefore, methods for obtaining quantitative error estimates, powerful though they may be, cannot replace physical insight. Used in the right context, as a tool for guiding the choice of a small number of model error parameters, covariance matching can be a useful addition to the repertory of tools available to oceanographers
Strength recovery in rocks and minerals : collaborative research by Brian Evans( Book )

1 edition published in 1992 in English and held by 3 WorldCat member libraries worldwide

Climate controls on coral growth in the Caribbean by Sara A Bosshart( Book )

2 editions published in 2013 in English and held by 3 WorldCat member libraries worldwide

Accurate predictions of Caribbean coral reef responses to global climate change are currently limited by a lack of knowledge of the dominant environmental controls on coral growth. Corals exhibit significant responses to environmental variability occurring on multi-annual to decadal timescales, which are significantly longer than the duration of typical laboratory and field-based experiments. Skeletal growth records, which provide annually-resolved histories spanning several centuries, enable links to be established between coral growth and both long term trends and low-frequency oscillations in environmental conditions. We used 3-D CT scan and imaging techniques to quantify the growth of 3 massive corals (Siderastrea siderea) from the US Virgin Islands (USVI) over the period 1950-2009 and compared these growth rates to other records collected from the USVI, Puerto Rico, the Yucatan, Belize and the Bahamas. While coral growth rates were inversely correlated to sea surface temperature (SST) in the Western Caribbean basin (Yucatan, Belize, Bahamas), we found no significant relationship between SST and coral growth in the Eastern basin (USVI, Puerto Rico). Instead, we found a significant inverse relationship between coral growth in the Western Caribbean and changes in the Atlantic Multidecadal Oscillation and a significant positive relationship between coral growth in the Eastern Caribbean Region and shifts in the Pacific Decadal Oscillation. Using data from the Simple Ocean Data Assimilation (SODA) we compared the wind field anomalies during periods of positive coral growth in both regions with the wind field anomalies during phases of these climactic modes that are conducive to coral growth. We find that both the AMO and the PDO play a significant role in shifting the mean wind patters in these Caribbean regions, with the PDO primarily affecting wind patters in the Eastern Basin and the AMO affecting wind patterns in the Western basin. We suggest that the altered wind patterns associated with these modes may induce upwelling favorable conditions in their respective regions of influence, increasing the availability of nutrients for coral growth
High sensitivity monitoring of resistivity and self-potential variations in the Palmdale and Hollister areas for earthquake studies by Theodore R Madden( Book )

1 edition published in 1990 in English and held by 2 WorldCat member libraries worldwide

Modeling convection in the Greenland Sea by Vikas Bhushan( Book )

1 edition published in 1998 in English and held by 2 WorldCat member libraries worldwide

A detailed examination of the development of a deep convection event observed in the Greenland Sea in 1988-89 is carried out through a combination of modeling, scale estimates, and data analysis. We develop a prognostic one-dimensional mixed layer model which is coupled to a thermodynamic ice model. Our model contains a representation of the lowest order boundary layer dynamics and adjustable coupling strengths between the mixed layer, ice, and atmosphere. We find that the model evolution is not very sensitive to the strength of the coupling between the ice and the mixed layer sufficiently far away from the limits of zero and infinite coupling; we interpret this result in physical terms. Further, we derive an analytical expression which provides a scale estimate of the rate of salinification of the mixed layer during the ice-covered preconditioning period as a function of the rate of ice advection. We also derive an estimate for the rate of the mixed layer deepening which includes ice effects. Based on these scale estimates and model simulations, we confirm that brine rejection and advection of ice out of the convection area were essential ingredients during the preconditioning process. We also demonstrate that an observed rise in the air temperature starting in late December 1988 followed by a period of moderately cold ~ -10*C temperatures was key to the development of the observed convection event. Finally, we show that haline driven deep convection underneath an ice cover is possible, but unlikely to occur in the Greenland Sea. On the basis of these results, we develop a coherent picture of the evolution of the convection process which is more detailed than that presented in any previous work. We also comment on the likelihood that deep convection occurred in the Greenland Sea in the past two decades from an examination of historical data, and relate these findings to what is known about the inter-annual variability of convective activity in the Greenland Sea
The influence of ridge geometry at the ultraslow-spreading Southwest Indian Ridge (9°-25°E) : basalt composition sensitivity to variations in source and process by Jared Jeffrey Standish( Book )

1 edition published in 2006 in English and held by 2 WorldCat member libraries worldwide

(Cont.) Along the orthogonally spreading supersegment (14 mm/yr) moderate degrees of partial melting effectively sample the bulk mantle source, while on the obliquely spreading supersegment (7-14 mm/yr) suppression of mantle melting to low degrees means that the bulk source is not uniformly sampled, and thus "process" rather than "source" dominates melt chemistry
An inverse approach to understanding benthic oxygen isotope records from the last deglaciation by Daniel Edward Amrhein( Book )

1 edition published in 2014 in English and held by 2 WorldCat member libraries worldwide

Observations suggest that during the last deglaciation (roughly 20,000-10,000 years ago) the Earth warmed substantially, global sea level rose approximately 100 meters in response to melting ice sheets and glaciers, and atmospheric concentrations of carbon dioxide increased. This interval may provide an analog for the evolution of future climate. The ocean plays a key role in the modern climate system by storing and transporting heat, salt, and nutrients, but its role during the last deglaciation remains uncertain. Prominent signals of the last deglaciation in the ocean are a gradual warming and a decrease of the seawater oxygen isotope ratio 18O (a signature of melting land ice sheets). These changes do not occur uniformly in the ocean, but propagate like plumes of dye over hundreds and thousands of years, the aggregate results of turbulent advective and diffusive processes. Information about changing temperatures and oxygen isotopes is stored in the shells of benthic organisms recovered in ocean sediment cores. This thesis develops and applies an inverse framework for understanding deglacial oxygen isotope records derived from sediment cores in terms of the Green functions of ocean tracer transport and ocean mixed layer boundary conditions. Singular value decomposition is used to find a solution for global mixed layer tracer concentration histories that is constrained by eight last-deglacial sediment core records and a model of the modern ocean tracer transport. The solution reflects the resolving power of the data, which is highest at model surface locations associated with large rates of volume flux into the deep ocean. The limited data resolution is quantified and rationalized through analyses of simple models. The destruction of information contained in tracers is a generic feature of advective-diffusive systems. Quantifying limitations of tracer records is important for making and understanding inferences about the long-term evolution of the ocean
Quantifying overwash flux in barrier systems : an example from Martha's Vineyard, Massachusetts, USA by Emily A Carruthers( Book )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Coastal barriers are particularly susceptible to the predicted effects of accelerated of sea-level rise and the potential for increased impacts of intense storms. Over centennial scales, barriers are maintained via overtopping during storms, causing deposition of washover fans on their landward sides. This study examines three washover fans on the south shore of Martha's Vineyard using a suite of data including vibracores, ground penetrating radar, high resolution dGPS, and LiDAR data. From these data, the volumes of the deposits were determined and range from 2.1-2.4 x 10⁴ m³. Two overwashes occurred during Hurricane Bob in 1991. The water levels produced by this storm have a return interval of ~28 years, resulting in an onshore sediment flux of 2.4-3.4 m³/m/yr. The third washover was deposited by a nor'easter in January 1997, which has a water level return interval of ~6 years, resulting in a flux of 8.5 m³/m/yr. These fluxes are smaller than the flux of sediment needed to maintain a geometrically stable barrier estimated from shoreline retreat rates, suggesting that the barrier is not in long-term equilibrium, a result supported by the thinning of the barrier over this time interval
Plagioclase preferred orientation in the layered mylonites : evaluation of flow laws for the lower crust by Luc Mehl( Book )

1 edition published in 2008 in English and held by 2 WorldCat member libraries worldwide

CSDP the seismology of continental thermal regimes. Final technical report, January 1, 1975-December 31, 1984( )

1 edition published in 1985 in English and held by 0 WorldCat member libraries worldwide

Research progress is reported in the development of new seismological tools to define and characterize the geometry, mechanical construction and mass transport process of a geothermal system, and their application to various geothermal systems including the Fenton Hill Hot Dry Rock System, New Mexico, Kilauea and Kilauea Iki, Hawaii, Mt. St. Helens, Washington, and Long Valley, California. (ACR)
 
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