All ICDP Publications with Abstracts
From parent-sysfolder "Publications" + 2 folder-levels deep
628.
Structure of the California Coast Ranges and San Andreas Fault at SAFOD from seismic waveform inversion and reflection imaging
Journal of Geophysical Research: Solid Earth,
112
(6)
2007
ISSN: 21699313
Publisher: Blackwell Publishing Ltd
Keywords:▾
crust-mantle boundary; crustal structure; prestack migration; San Andreas Fault; seismic reflection; seismic refraction; seismic tomography; seismic wave; waveform analysis, California; North America; Parkfield; United States
Abstract: ▾ A seismic reflection and refraction survey across the San Andreas Fault (SAF) near Parkfield provides a detailed characterization of crustal structure across the location of the San Andreas Fault Observatory at Depth (SAFOD). Steep-dip prestack migration and frequency domain acoustic waveform tomography were applied to obtain highly resolved images of the upper 5 km of the crust for 15 km on either side of the SAF. The resulting velocity model constrains the top of the Salinian granite with great detail. Steep-dip reflection seismic images show several strong-amplitude vertical reflectors in the uppermost crust near SAFOD that define an ∼2-km-wide zone comprising the main SAF and two or more local faults. Another prominent subvertical reflector at 2-4 km depth ∼9 km to the northeast of the SAF marks the boundary between the Franciscan terrane and the Great Valley Sequence. A deep seismic section of low resolution shows several reflectors in the Salinian crust west of the SAF. Two horizontal reflectors around 10 km depth correlate with strains of seismicity observed along-strike of the SAF. They represent midcrustal shear zones partially decoupling the ductile lower crust from the brittle upper crust. The deepest reflections from ∼25 km depth are interpreted as crust-mantle boundary. Copyright 2007 by the American Geophysical Union.
627.
Scientific drilling of active faults: Past and future
Publisher
Springer Berlin Heidelberg
2007
626.
Supplementary material to B. Heim et al.(2008): Assembly and concept of a web-based GIS within the paleoclimate project CONTINENT (Lake Baikal, Siberia)
625.
Scientific drilling of active faults: Past and future
Publisher
Springer Berlin Heidelberg
2007
624.
Continental drilling and the study of impact craters and processes - An ICDP perspective
Publisher
Springer Berlin Heidelberg
2007
623.
Continental drilling and the study of impact craters and processes - An ICDP perspective
Publisher
Springer Berlin Heidelberg
2007
622.
Continental drilling and the study of impact craters and processes - An ICDP perspective
Publisher
Springer Berlin Heidelberg
2007
621.
620.
Natural resources
Publisher
Springer Berlin Heidelberg
2007
619.
Phytoplankton response to climate changes in Lake Baikal during the Holocene and Kazantsevo Interglacials assessed from sedimentary pigments
Journal of Paleolimnology,
37
(2)
177 – 203
2007
ISSN: 09212728Keywords:▾
Buryatia; Eurasia; Lake Baikal; Russian Federation; Selenga Delta; Bacillariophyta; Chlorophyceae; abundance; chlorophyll; climate change; Holocene; interglacial; lacustrine deposit; organic carbon; paleoecology; phytoplankton; pigment; pristine environment
Abstract: ▾ Lake Baikal, an ancient pristine lake in Siberia, has accumulated sediment deposits that span 25 million years. These deposits have the potential to provide a long-term record of climate changes and their interaction with the ecology of the lake. In order to investigate whether sedimentary phytoplankton pigments could be used to reconstruct past changes in total phytoplankton abundance and productivity, we compared the spatial variability in sedimentary pigment distributions in Holocene cores from three separate regions of the lake; Vidrino in the south, Posolski on Selenga Delta and Continent Ridge in the north. Furthermore, we present the first continuous sedimentary pigment and organic carbon sequence of the Kazantsevo interglacial (roughly a time equivalent to the European Eemian, and Marine Isotopic Stage MIS5e) at a resolution of approximately 150 years. Results of the spatial study showed marked differences in the sediment pigment deposition. Lowest chlorophyll a plus its degradation products versus organic carbon ratios (Chlas/TOC) indicating lowest production, but highest variability with time (indicating strongest climatic oscillations) were found at Continent Ridge. The study of sedimentary pigments deposited during the last two interglacial periods at Continent Ridge showed Chlas/TOC ratios 50-1000 times higher during the Kazantsevo Interglacial compared to the glacial periods, whereas the TOC content was only five times higher, thus indicating the significance of the Chlas/TOC ratio for the reconstruction of the phytoplankton abundance and productivity. Strong oscillations occurred during the Kazantsevo Interglacial within centennial time scales. Chlorophyllb plus its degradation products provided additional information on the past development of Chlorophyceae. Highest Chlas/TOC ratios were found during the early Holocene at approximately 9 kyr BP. Indications of short phytoplankton production maxima were also found during the late Atlantic (6 kyr BP) and at the Subboreal/Subatlantic transition (3 kyr BP). From this we conclude that sedimentary chlorophyll a is a reliable indicator of phytoplanktonic response to climate changes and may serve for validation of future climate scenarios in continental regions. © 2006 Springer Science+Business Media B.V.
618.
The Role of Fault Zone Drilling
Volume 4
Publisher
Elsevier
2007
617.
10.06 - Exogenic Dynamics, Cratering and Surface Ages
Volume 1-10
2007
616.
[English]
Broadside interferometric and reverse-time imaging of the San Andreas Fault
Page 2175-2179
Publisher
Society of Exploration Geophysicists
2007
Center for Wave Phenomena, Colorado School of Mines, Golden, CO 80401, United States; Earth and Ocean Sciences Division, Duke University, Durham, NC 27708, United States; Paulsson Geophysical Services, Inc., Brea, CA 92821, United StatesISBN:
9781604238976
615.
[English]
Characterisation and engineering properties of methane hydrate soils
Volume 3-4
,
Page 2591-2642
2007
University of Cambridge, Cambridge, United Kingdom; Technion, Israel Institute of Technology, Haifa, IsraelISBN:
9780415402675
614.
[English]
Integrated petrophysical and borehole seismic studies of Lake Bosumtwi impact crater, Ghana
Volume 26
,
Page 447 – 451
Publisher
Society of Exploration Geophysicists
2007
Keywords:▾
Lakes; Pore size; Rocks; Seismic waves; Seismology; Shear waves; Bimodal distribution; Different sizes; Geophysical logging; Impact structures; Interstitial materials; Laboratory measurements; Linear relationships; Seismic measurements; Seismic prospecting
ISBN:
978-160423897-6
613.
[English]
Migration-based location of the SAFOD target-earthquakes
Volume 2
,
Page 797-801
Publisher
Society of Petroleum Engineers
2007
Berlin Free UniversityISBN:
9781605601557
612.
[English]
Monitoring microearthquakes with the San Andreas fault observatory at depth
Volume 2
,
Page 747-751
Publisher
Society of Petroleum Engineers
2007
NORSAR; USGSISBN:
9781605601557
611.
[English]
Sulfur geochemistry in the HSDP2 drilling, Hawaii: Effects of lava degassing and sea-water interaction
Volume 1
,
Page 61 – 64
2007
ISBN:
978-041545135-2
610.
Continental drilling and the study of impact craters and processes - An ICDP perspective
2007
609.
μ-Synchrotron radiation excited X-ray fluorescence microprobe trace element studies on spherules of the Cretaceous/Tertiary boundary transitions of NE-Mexico and Haiti samples
Spectrochimica Acta - Part B Atomic Spectroscopy,
62
(8)
824-835
2007
Abstract: ▾ Synchrotron radiation, collimated to a μm scale was used for the determination of trace elements in micro-tektites and spherule material for the first time. The experimental set-up of the SXRF microprobe at beamline L at HASYLAB at DESY offers a suitable method for performing non-destructive in situ multi-element analysis focusing on spatial trace element distributions and mineral phases of the melted ejecta material from the Cretaceous/Tertiary boundary. The spatial distribution of trace elements was determined in melt inclusions as well as in phase transitions in selected parts of chlorite-smectite spherules and tektite glass material by using a beam with a diameter of 15 μm collimated with a glass capillary for line- and area scans as well as for single point measurements for elements with Z between 19 and 92. The analyzed spherules show alteration features but also zonation and carbonate inclusions, originating from the Chicxulub impact event. These initial results demonstrate the potential of μ-SXRF analysis for the discrimination of alteration and primary signals of the spherules and re-construction of their genetic evolution. It could be shown that the spherules represent a complex mixture of different materials from the subsurface at the Chicxulub impact site. © 2007 Elsevier B.V. All rights reserved.
608.
Talc-bearing serpentinite and the creeping section of the San Andreas fault
Nature,
448
(7155)
795-797
2007
ISSN: 00280836
Publisher: Nature Publishing Group
Keywords:▾
mineral; serpentine; talc, creep; fault slip; fault zone; hydrothermal fluid; San Andreas Fault; serpentinite; shear strength; sliding; talc; ultramafic rock, article; chemical reaction; friction; gravity; priority journal; rock; temperature, California; Cholame Valley; North America; San Juan Bautista; San Luis Obispo County; United States
Abstract: ▾ The section of the San Andreas fault located between Cholame Valley and San Juan Bautista in central California creeps at a rate as high as 28 mm yr -1 (ref. 1), and it is also the segment that yields the best evidence for being a weak fault embedded in a strong crust. Serpentinized ultramafic rocks have been associated with creeping faults in central and northern California, and serpentinite is commonly invoked as the cause of the creep and the low strength of this section of the San Andreas fault. However, the frictional strengths of serpentine minerals are too high to satisfy the limitations on fault strength, and these minerals also have the potential for unstable slip under some conditions. Here we report the discovery of talc in cuttings of serpentinite collected from the probable active trace of the San Andreas fault that was intersected during drilling of the San Andreas Fault Observatory at Depth (SAFOD) main hole in 2005. We infer that the talc is forming as a result of the reaction of serpentine minerals with silica-saturated hydrothermal fluids that migrate up the fault zone, and the talc commonly occurs in sheared serpentinite. This discovery is significant, as the frictional strength of talc at elevated temperatures is sufficiently low to meet the constraints on the shear strength of the fault, and its inherently stable sliding behaviour is consistent with fault creep. Talc may therefore provide the connection between serpentinite and creep in the San Andreas fault, if shear at depth can become localized along a talc-rich principal-slip surface within serpentinite entrained in the fault zone. ©2007 Nature Publishing Group.
607.
The Lake Bosumtwi impact structure in Ghana: A brief environmental assessment and discussion of ecotourism potential
Meteoritics and Planetary Science,
42
(4-5)
561 – 567
2007
ISSN: 10869379
Publisher: University of Arkansas
Abstract: ▾ Lake Bosumtwi is a natural inland freshwater lake that originated from a meteorite impact. The lake is becoming a popular tourist attraction in Ghana and has the potential to be developed as an ecotourism site in the future. However, there have been some unregulated human activities and unplanned infrastructure development, and there are increased levels of pollutants in the lake water. In order to make ecotourism at Lake Bosumtwi successful in the long term, the Lake Bosumtwi Development Committee has been formed to ensure that local people are empowered to mobilize their own capacities. It has been realized that an important criterion required to develop ecotourism in a socially responsible, economically efficient, and environmentally viable way is to foster a constructive dialogue between the local people and tourists about the needs of the indigenous people. © The Meteoritical Society, 2007. Printed in USA.
606.
The Campi Flegrei deep drilling project
Scientific Drilling
(4)
48 – 50
2007
ISSN: 18163459605.
The Chicxulub impact event and its environmental consequences at the Cretaceous-Tertiary boundary
Palaeogeography, Palaeoclimatology, Palaeoecology,
255
(1-2)
4-21
2007
Abstract: ▾ An impact-mass extinction hypothesis for the Cretaceous-Tertiary (K/T) boundary transition has been confirmed with multiple lines of evidence, beginning with the discovery of impact-derived Ir in K/T boundary sediments and culminating in the discovery of the Chicxulub impact crater. Likewise, a link between the Chicxulub impact crater and K/T boundary sediments has been confirmed with multiple lines of evidence, including stratigraphic, petrological, geochemical, and isotopic data. The environmental effects of the Chicxulub impact event were global in their extent, largely because of the interaction of ejected impact debris with the atmosphere. The environmental consequences of the Chicxulub impact event and their association with the K/T boundary mass extinction event indicate that impact cratering processes can affect both the geologic and biologic evolution of our planet. © 2007 Elsevier B.V. All rights reserved.
604.