808 research outputs found
Introduction to Cenozoic Antarctic glacial history
No full textFluctuations in size of the Antarctic Ice Sheet (AIS), a feature of the
southern high latitudes for at least the last 35 million years, have been
one of the major driving forces of changes in global sea level and
climate through the Cenozoic Era. Under the prospect of a warming
climate (IPCC, 2007), it is important to assess the past and future
stability of the cryosphere, particularly after ice core records identified
a direct link between variations in CO2 concentration in the
atmosphere and palaeotemperatures.
This special issue of Global and Planetary Change developed
largely from contributions presented at the EGU meeting in Vienna,
Austria (http://meetings.copernicus.org/egu2008/; 13–18 April,
2008), and at the International Geological Congress (IGC) Conference
in Oslo, Norway (www.33igc.org/; 6–14 August, 2008) where we
organised sessions designed to investigate the many orders and scales
of variation of Antarctic ice sheets and palaeoclimate from Antarctic
and Subantarctic records, from outcrop studies, deep sea drilling,
continental margin drilling and seismic investigations, permafrost
and ice core drilling.
This special issue of Global and Planetary Change continues a
series of related special issues and a book (Florindo et al., 2003, 2005;
Barrett et al., 2006; Florindo et al., 2008; Florindo and Siegert, 2009),
all of which are linked to the Antarctic Climate Evolution (ACE)
project. ACE is an initiative of the Scientific Committee on Antarctic
Research (SCAR) to investigate the climate and glacial history of
Antarctica by linking climate and ice sheet modelling studies with
terrestrial and marine geological and geophysical evidence of past
changes (www.scar.org/researchgroups/geoscience/ace; http://www.
ace.scar.org). Over the coming years, ACE will pursue a broad range of
objectives to better comprehend past Antarctic changes through
organisation of workshops and publication of special issues, allowing
the dissemination of geological data and numerical modelling to a
wide audience.Publishedv-vii1.8. Osservazioni di geofisica ambientale2.2. Laboratorio di paleomagnetismo3.8. Geofisica per l'ambienteJCR Journalreserve
Mecenazgo y edición en la primera mitad del siglo XVI: el Florindo de Fernando Basurto (Zaragoza: Pedro Hardouin, 1530)
No full textSe analizan las funciones del editor y del mecenas en la publicación de libros impresos en el siglo XVI. Para esto se estudia en profundidad la actividad de Fernando Basurto, autor, y de Juan Fernández de Heredia, mecenas-editor, en torno a la primera edición del Florindo publicado por Pedro Hardouin en Zaragoza en 1530.
The paper discusses the functions of the publisher and patron in the publication of printed books during the 16th Century. With this purpose, the activity of Fernando Basurto, author, and Juan Fernandez de Heredia, patron-editor, about the fi rst edition of Florindo published in Zaragoza by Pedro Hardouin in 1530 is studied
Mecenazgo y edición en la primera mitad del siglo XVI: el Florindo de Fernando Basurto (Zaragoza: Pedro Hardouin, 1530)
No full textThe paper discusses the functions of the publisher and patron in the publication of printed books during the 16th Century. With this purpose, the activity of Fernando Basurto, author, and Juan Fernandez de Heredia, patron-editor, about the first edition of Florindo published in Zaragoza by Pedro Hardouin in 1530 is studied. Se analizan las funciones del editor y del mecenas en la publicación de libros impresos en el siglo XVI. Para esto se estudia en profundidad la actividad de Fernando Basurto, autor, y de Juan Fernández de Heredia, mecenas-editor, en torno a la primera edición del Florindo publicado por Pedro Hardouin en Zaragoza en 1530.
COMMENT & REPLY - Comment on “Could the Mw = 9.3 Sumatra Earthquake Trigger a Geomagnetic Jerk?”
No full textWe thank M. Dumberry for providing the
opportunity to discuss further the article
[Florindo et al., 2005] in which we suggested
that the Sumatra earthquake could have triggered a geomagnetic jerk. Dumberry is against our hypothesis for different reasons: (1) The displacement pattern produced by this earthquake is incompatible with the core-mantle boundary (CMB) deformations required for a torsional oscillation; (2) most of the deformations occurred locally, producing an actual mass displacement that has not involved the entire Earth; and (3) no abrupt change in the length of day (LOD) has been observed after this event. Although we agree with some of the considerations
proposed by Dumberry, we think that these do not rule out the possibility that a jerk
has been triggered by the Sumatra earthquake
or that in the future, other earthquakes could induce a change in the flow pattern near the CMB leading to a geomagnetic jerk. On the contrary, we retain that this hypothesis is plausible, although it is more correct to talk about the existence of a possible link between geomagnetic jerks and earthquakes where the earthquake magnitude is not the only discriminating parameter.Published3433.3. Geodinamica e struttura dell'interno della Terra3.4. GeomagnetismoN/A or not JCRreserve
Anomalous last interglacial Tyrrhenian sea levels and Neanderthal settling at Guattari and Moscerini caves (central Italy)
No full textWe present a geological-stratigraphical study aimed to provide chronologic constraints to the sea-level markers occurring at two coastal caves of central Italy (Grotta Guattari and Grotta dei Moscerini) and to the Neanderthal frequentation of these caves, in the light of recent archaeological and geomorphological-geochronological studies suggesting similar sea levels during MIS 5.5 and MIS 5.3, and only few m below the Present during MIS 5.1 in this region. Based on the review of previous literature data, combined with new stratigraphic observations at Grotta Guattari and re-analysis of archive material including unpublished field notes from Grotta dei Moscerini, we reconstruct a plausible sea-level history accounting for the lithological and paleoenvironmental features of their sedimentary fillings. In particular, we outline the abundant occurrence of well-rounded pumice clasts within the sedimentary deposits of Moscerini Cave, attesting for the proximity to the beach where this pumice was gathered by wave action. Through the petrographic and geochemical analysis of this pumice we evidence provenance from Phlegraean Fields and Ischia Island volcanic districts, framing their chronology in the time span 118–40 ka, consistent with literature ESR-U/Th dates providing ages ranging 101 ± 5–74 ± 7 ka for the sedimentary filling of both Moscerini and Guattari caves
Magnetite dissolution in siliceous sediments
No full textMagnetite dissolution, and consequent loss of magnetization, is widely observed in reducing sedimentary environments, where the decrease in Eh-pH values with depth is driven by bacterially mediated degradation of organic carbon. We have observed low magnetizations in sediments with elevated pore water silica concentrations that arise from diagenesis of biogenic silica and/or silicic volcanic ash. These depletions in magnetization are greater than can be accounted for by dilution with magnetite-poor sediments and suggest that postdepositional destruction of magnetite has occurred. Biosiliceous sediments usually also contain elevated concentrations of organic carbon, which makes it difficult to separate organic-carbon-related magnetite dissolution from other possible mechanisms for magnetite dissolution. However, the extent of magnetite dissolution in the sedimentary sequences that we have studied is not obviously related to the redox-state of the environment. This suggests that other mechanisms might have given rise to magnetite dissolution in these siliceous sediments. Thermodynamic calculations indicate that magnetite is unstable under conditions of elevated dissolved silica concentrations (and appropriate Eh-pH conditions) and predict that magnetite will break down to produce iron-bearing smectite. A survey of magnetic susceptibility and pore water geochemical data from widely distributed Ocean Drilling Program sites supports this observed link between high dissolved silica concentrations and low magnetic susceptibilities. This observed link also holds for environments with low biogenic silica productivity (and low organic carbon content) but with high interstitial silica concentrations due to dissolution of silicic volcanic ashes. Dissolution of magnetite is therefore predicted to be a common feature of siliceous sedimentary environments
Inverse to normal magnetic fabric transition in a Upper Miocene marly sequence from Tuscany, Italy
No full textThe magnetic susceptibility fabric of an upper Miocene marry sequence exposed along the Morra creek (Tuscany, Italy) changes from inverse (maximum susceptibility axis sub-perpendicular to bedding) to normal from the bottom to the top of the section. The change is gradual, with the presence of anomalous magnetic susceptibility fabrics at some levels. The anhysteretic remanence anisotropy is always normal throughout the sequence. The changes in the magnetic fabric seem to be controlled by sedimentological variations, with the inverse susceptibility fabric related to the abundance of iron-bearing carbonates in the lower part of the section. In the upper part of the section subtle changes in the detrital inputs in the basin, and particularly a larger contribution of clayey and ferrimagnetic particles, turned the susceptibility fabric to a normal type
Risultati di un'indagine interdisciplinare (analisi di facies, biostratigrafia, magnetostratigrafia) svolta su due sezioni della Val di Fine (Toscana, Pisa) di età compresa tra il Miocene superiore ed il Pliocene inferiore
No full textPengaruh Motivasi Kerja, Disiplin Kerja, dan Kompensasi Terhadap Kinerja Karyawan. ( Studi Kasus Karyawan PT. Florindo Makmur (SB 7))
No full textTemuan ini mengidentifikasi kaitan antara motivasi kerja, disiplin kerja, serta kompensasi pada kinerja karyawan di PT. Florindo Makmur (SB7). Metode penelitian ini adalah kuantitatif, penentuan jumlah sampel dilakukan melalui teknik Total Sampling. Populasi diambil dari Karyawan PT. Florindo Makmur (SB7). Ukuran populasi yang diketahui adalah 40 karyawan. Lokasi penelitian dilakukan di PT. Florindo Makmur (SB7) Kecamatan Seputihbanyak, Lampung Tengah, Lampung. Penelitian dilakukan dalam jangka waktu November-Desember 2024. Besarnya penentuan jumlah sampel menggunakan sampel jenuh. Data primer diambil menggunakan kuisioner via google form dan pertanyaan yang diambil sesuai dengan setiap indikator variabel menggunakan metode skala Likert (1-4). Data sekunder bersumber dari penelitian jurnal terdahulu yang menggunakan metode kuantiatif sesuai dengan topik temuan ini. Temuan ini menerapkan Uji Instrument yaitu Uji Validitas, Uji Reliabilitas. Uji Asumsi Klasik yaitu Uji Normalitas, UjiMultikolinearitas,Uji Heteroskedastisitas. Serta analisis regresi linier berganda serta pengujian hipotesis melalui Uji t parsial dan Uji F simultan dan Koefisien Determinasi (R2) serta IBM SPSS Statistics 23. Hasil uji koefisien determinasi (R²) menunjukkan bahwa ketiga variabel tersebut secara signifikan mempengaruhi kinerja karyawan sebesar 59,6% pada kinerja karyawan di PT. Florindo Makmur (SB7)
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