{ "144791-21895848": { "datetime_modified":"20260129T135258", "datetime_start":"20260210T090000", "datetime_end":"20260210T100000", "has_end_time":1, "date_start":"2026-02-10", "date_end":"2026-02-10", "time_start":"09:00:00", "time_end":"10:00:00", "time_zone":"America\/Detroit", "event_title":"Alex Quizon Dissertation Defense", "occurrence_title":"", "combined_title":"Alex Quizon Dissertation Defense: Clumped and traditional stable isotope proxy innovations for paleoclimatic and paleoceanographic reconstructions", "event_subtitle":"Clumped and traditional stable isotope proxy innovations for paleoclimatic and paleoceanographic reconstructions", "event_type":"Lecture \/ Discussion", "event_type_id":"13", "description":"Stable oxygen isotope measurements (\u03b418O) are important tools in studies of climate, oceanography, and hydrology of today and the past. \u03b418O in fossil marine carbonates (\u03b418Ocarb) is used to reconstruct past ocean temperatures, and seawater \u03b418O (\u03b418Ow) tracks with salinity and is thus used to interpret hydrological variability. However, \u03b418Ocarb-temperature estimates rely on assumptions of how \u03b418Ow varied in the past, which remains uncertain. \u2018Clumped\u2019 isotope thermometry (\u039447) measurements are independent of \u03b418Ow, allowing us to circumvent this uncertainty and to simultaneously reconstruct past ocean temperatures and \u03b418Ow when combined with \u03b418Ocarb. This dissertation explores innovations in the utility of these isotopic tools. First, we investigated the viability of \u039447 paleothermometry in marine gastropods - an archive largely unexplored for \u039447-paleotemperature reconstructions (Chapters 2 & 3). Second, we explored the utility of \u03b418Ow and \u039447-derived paleo-\u03b418Ow as tracers of ocean currents (Chapters 4 & 5) and ice sheet melt (Chapter 6).\n\nChapter 2 documents \u039447-T\u2019s from a suite of modern marine gastropods collected from localities spanning the globe. Our findings suggest that many gastropods precipitate in isotopic equilibrium and accurately record environmental temperatures. However, some gastropods - notably Caviturritella\/Turritella (turritellids) and Campanile - appear to precipitate out of equilibrium (\u201cvital effects\u201d) and thus exhibit \u039447-T\u2019s cooler than actual environmental temperatures.\n\nChapter 3 expands on the finding from Chapter 2 that turritellids appear to exhibit a vital effect-induced cold bias of ~6\u00b0C, reporting \u039447-temperatures from 2 modern and 7 fossil (Mid-Miocene, ~18-14 Ma) turritellids from Colombia. The \u039447 data from the modern turritellids corroborate the previous finding of a ~6\u00b0C cold bias. After a +6\u00b0C adjustment is applied to Mid-Miocene \u039447-temperatures, adjusted \u039447-temperatures align with previous paleotemperature estimates in the region from other studies, highlighting the potential of vital effect-based corrections.\n\nChapter 4 explores the utility of \u03b418Ow as a tracer for the Labrador and Gulf Stream boundary currents in the North Atlantic. We collected 358 new salinity and \u03b418Ow measurements along the Eastern Seaboard, doubling the number of existing data in the region. Our paired salinity and \u03b418Ow data show distinct signatures for the Labrador Current and Gulf Stream roughly separated at Cape Hatteras, North Carolina, creating the framework for using \u03b418Ow as a tracer of these currents.\n\nChapter 5 expands on the findings from Chapter 4, as we discuss the ability of \u039447-derived paleo-\u03b418Ow to track the Labrador Current and Gulf Stream in the past. We measured fossil quahogs (Mercenaria sp., ~130-115 ka and ~80 ka) from localities along the Eastern Seaboard and found that, despite temporal differences, paleo-\u03b418Ow latitudinal trends generally align with the modern \u03b418Ow latitudinal gradient. Thus, these findings showcase the potential of \u039447-derived paleo-\u03b418Ow to track water masses from the past.\n\nChapter 6 builds on the framework of using \u039447-derived paleo-\u03b418Ow to interpret paleohydrological variability, as we infer substantial ice sheet melt at Nantucket, Massachusetts during the Last Interglacial (~130-115 ka). We measured 7 Mercenaria across 2 units at this locality and observed paleo-\u03b418Ow values significantly depleted relative to modern values, which is consistent with substantial freshwater input (i.e., ice sheet melt).\n\nAltogether, this dissertation builds on the existing framework of \u039447 and \u03b418Ow as paleoclimatic and paleoceanographic tools by investigating the viability of marine gastropods for \u039447-paleotemperature reconstructions and exploring \u039447-derived paleo-\u03b418Ow as a tracer of ocean circulation and ice sheet melt in the past.", "occurrence_notes":null, "guid":"144791-21895848@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/144791", "building_id":"1000188", "building_name":"1100 North University Building", "campus_maps_id":"628", "room":"2540", "location_name":"1100 North University Building", "has_livestream":0, "cost":"", "tags":["Earth And Environmental Sciences"], "website":"", "sponsors":[ { "group_name":"Earth and Environmental Sciences", "group_id":"3170", "website":"http:\/\/www.lsa.umich.edu\/earth" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2026\/01\/event_144791_original-1.jpg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2026\/01\/event_144791_original-1.jpg" }, "occurrence_count":1, "first_occurrence":21895848 } , "134855-21895919": { "datetime_modified":"20260224T144435", "datetime_start":"20260210T090000", "datetime_end":"20260210T100000", "has_end_time":1, "date_start":"2026-02-10", "date_end":"2026-02-10", "time_start":"09:00:00", "time_end":"10:00:00", "time_zone":"America\/Detroit", "event_title":"Chair Aerobics\/Stretch, Strength & Balance\/Zumba", "occurrence_title":"", "combined_title":"Chair Aerobics\/Stretch, Strength & Balance\/Zumba", "event_subtitle":"", "event_type":"Exercise \/ Fitness", "event_type_id":"6", "description":"Lifetime Fitness classes are offered at Briarwood Mall in the JCPenney wing every Monday-Friday from 9-10am. No experience necessary. Classes are specifically designed for older adults, however, everyone is welcome. LTF classes are free, but please consider making a $2\/person per class donation as our classes are supported strictly through donations. No registration is necessary, simply attend when it fits your schedule.", "occurrence_notes":"LTF classes are held in the court near JCPenney, Monday through Friday", "guid":"134855-21895919@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/134855", "building_id":"null", "building_name":"Off Campus Location", "campus_maps_id":"1", "room":"", "location_name":"Briarwood Mall", "has_livestream":0, "cost":"", "tags":["fitness","Health & Wellness"], "website":"https:\/\/www.kines.umich.edu\/about\/community-programs\/lifetime-fitness", "sponsors":[ { "group_name":"Kinesiology Community Programs", "group_id":"1192", "website":"https:\/\/www.kines.umich.edu\/about\/community-programs" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2025\/04\/event_134855_original-1.png", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2025\/04\/event_134855_original-1.png", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2025\/04\/event_134855_original-1.png", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2025\/04\/event_134855_original-1.png", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2025\/04\/event_134855_original-1.png", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2025\/04\/event_134855_original-1.png", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2025\/04\/event_134855_original-1.png" }, "occurrence_count":172, "first_occurrence":21875405 } }