georefid:2002-010613georefid:2002-010596SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2002-010613<gco:CharacterString>Characterization of the upper oceanic crust using high-resolution seismic amplitude modeling</gco:CharacterString>2000-01-01publicationgeorefid:2002-010613Sun, Yue-FengLamont-Doherty Earth Observatory, Palisades, NY, United StatesauthorGoldberg, DavidUniversity of California at Davis, United StatesauthorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyIn: Dilek, Yildirim (editor), Moores, Eldridge M. (editor), Elthon, Don (editor), Nicolas, Adolphe (editor), Ophiolites and oceanic crust; new insights from field studies and the Ocean Drilling Program349203-210We examine the links between structural and lithological changes in the upper oceanic crust and seismic amplitude changes by applying modeling techniques in order to extend the conventional uses and limits of seismic data. Using high-resolution velocity and density borehole profiles from Ocean Drilling Program Hole 504B, we evaluate modeling methods and study the mechanisms of seismic attenuation in this layered porous environment. Good agreement of full-waveform synthetic seismograms with field seismic data is observed in travel time as well as in waveform shape and amplitude variations. Large seismic energy losses in the upper oceanic crust are observed where the formation consists of cyclic sequences of high- and low-porosity units, which demonstrates that energy loss in the upper oceanic crust is dominated by the effects of scattering alone. A fault zone and the boundary between seismic layers 2 and 3 are observed by amplitude changes on both synthetic and observed reflection records. The seismic amplitude, therefore, may indeed be used to map porosity and other lithologic variations.completedSolid-earth geophysicsamplitudeattenuationCosta Rica RiftcrustDeep Sea Drilling Projectdownhole methodsDSDP Site 504East Pacificelastic wavesgeophysical methodsgeophysical profilesgeophysical surveyshigh-resolution methodsIPODLeg 111Leg 137Leg 140Leg 148Leg 69Leg 70Leg 83Leg 92mathematical modelsmodelsOcean Drilling Programoceanic crustPacific Oceanporosityseismic methodsseismic profilesseismicitysurveysupper crusturn:org.iodp:exp:111urnlargerWorkCitationcampaignurn:org.iodp:exp:137urnlargerWorkCitationcampaignurn:org.iodp:exp:140urnlargerWorkCitationcampaignurn:org.iodp:exp:148urnlargerWorkCitationcampaignurn:org.iodp:exp:69urnlargerWorkCitationcampaignurn:org.iodp:exp:70urnlargerWorkCitationcampaignurn:org.iodp:exp:83urnlargerWorkCitationcampaignurn:org.iodp:exp:92urnlargerWorkCitationcampaignurn:org.iodp:exp:69:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:69urnlargerWorkCitationcampaignurn:org.iodp:exp:70:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:70urnlargerWorkCitationcampaignurn:org.iodp:exp:83:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:83urnlargerWorkCitationcampaignurn:org.iodp:exp:92:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:92urnlargerWorkCitationcampaignurn:org.iodp:exp:111:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:111urnlargerWorkCitationcampaignurn:org.iodp:exp:137:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:137urnlargerWorkCitationcampaignurn:org.iodp:exp:140:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:140urnlargerWorkCitationcampaignurn:org.iodp:exp:148:site:504urnlargerWorkCitationstudyurn:org.iodp:exp:148urnlargerWorkCitationcampaignEnglishgeoscientificInformation-83.4357-83.43481.13351.1338Includes appendices