Article
Geochemistry & Geophysics
Brendan T. Reilly, Joseph S. Stoner, Saedis Olafsdottir, Anne Jennings, Robert Hatfield, Greta Bjork Kristjansdottir, Aslaug Geirsdottir
Summary: We investigated the amplitude and frequency of geomagnetic change in the Northern North Atlantic region over the past 15 thousand years. Using high-resolution sediment cores, we validated prior results and provided stronger geochronological constraints on the paleomagnetic secular variation signal. Our study also revealed greater variability and higher amplitudes on centennial timescales, which is important for understanding the geodynamo.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Environmental Sciences
Partha Sarathi Jena, Ravi Bhushan, Shivam Ajay, Nisha Bharti, A. K. Sudheer
Summary: The study using marine sediment core and AMS technology shows that the estimation of Be-10 depositional flux is significantly affected by local processes, leading to a notable discrepancy between model-derived deposition rates and measured values. Moreover, variations in Be-10 depositional flux and the Be-10/Be-9 ratio over the past 43 ka demonstrate the impact of changes in Earth's magnetic field.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geochemistry & Geophysics
Gabriel West, Andreas Nilsson, Alexis Geels, Martin Jakobsson, Matthias Moros, Francesco Muschitiello, Christof Pearce, Ian Snowball, Matt O'Regan
Summary: This study investigates the behavior of the geomagnetic field in polar regions during the late Holocene period. By analyzing well-dated sediment cores from the Chukchi Sea, Arctic Ocean, the authors provide valuable insights into the changes in the geomagnetic field in the Arctic over the past few thousand years.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Annemarieke Beguin, Adriano Pimentel, Lennart de Groot
Summary: By analyzing and integrating new paleomagnetic data from Pico Island in the Azores Archipelago, this study successfully constructed a curve of the direction and intensity changes of the Earth's magnetic field over the past two thousand years. The research revealed a period of low inclination between AD 900 and 1560, with minimum values of 32 degrees.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Steve Lund
Summary: This study develops composite high-resolution, full-vector PSV records for the last 380 ka from three regions in the western North Atlantic Ocean, identifying common features and excursions. The findings provide important insights into the evolution of Earth's magnetic field.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2022)
Article
Geochemistry & Geophysics
Torsten Haberzettl, Thomas Kasper, Joseph S. Stoner, Jean Jacques Rahobisoa, Gerhard Daut
Summary: The paleomagnetic records derived from maar lakes in Madagascar provide valuable insights into the paleomagnetic secular variations in (southern) Africa, showing similarities with global geomagnetic field reconstructions and other geological records. These new data help distinguish reliable paleomagnetic data from potentially problematic ones, improving the understanding of paleomagnetic changes in the region.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geography, Physical
Venera Dobrica, Cristiana Stefan, Crisan Demetrescu
Summary: This study examined the Earth's surface magnetic field and its secular variation, focusing on the internal constituents and dynamics of the SV foci. By analyzing long time-span geomagnetic models and applying filtering techniques, the study revealed new features of the Earth's surface field evolution, such as the westward drift of the inter-centennial constituent and the westward drift of higher frequency constituents in the equatorial band.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geography, Physical
Bernardo S. Chede, Igor M. Venancio, Thiago S. Figueiredo, Ana Luiza S. Albuquerque, Emmanoel Vieira Silva-Filho
Summary: The study reveals changes in mercury deposition and accumulation in the marine realm over the last 70 ka, with significant influence of climate change and deep ocean circulation on the geochemical cycle of mercury in marine sediments.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geography, Physical
Bernardo S. Chede, Igor M. Venancio, Thiago S. Figueiredo, Ana Luiza S. Albuquerque, Emmanoel Vieira Silva-Filho
Summary: This study investigates the deposition and accumulation changes of mercury in marine sediments in the western tropical South Atlantic over the last 70 ka. The results show higher concentrations of mercury during the glacial period due to increased atmospheric dust. The increased residence time of North Atlantic Deep Water reduces mercury concentration, and the terrigenous input from the Sao Francisco River further dilutes mercury during Heinrich stadials. The study highlights the strong influence of deep ocean circulation on the long-term deposition and accumulation of mercury in marine sediments.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geography, Physical
Steve Lund, Ellen Platzman, Chris Scholz
Summary: A paleomagnetic study was conducted on three piston cores from Lake Turkana to recover a Holocene paleomagnetic secular variation (PSV) record and correlate it with other PSV records from the East Africa Rift Valley. Magnetic measurements were made on the cores, and the resulting records could be correlated. The sediment ages were estimated through PSV age estimation and radiocarbon dating, and showed good consistency. The Lake Turkana PSV record is the highest resolution directional record of PSV ever recovered from Africa.
Article
Geosciences, Multidisciplinary
Costanza Del Gobbo, Renato R. Colucci, Giovanni Monegato, Manja Zebre, Filippo Giorgi
Summary: This study investigates the physical processes sustaining Alpine glaciers during the Last Glacial Maximum (LGM) using a regional climate model. The results show increased summer convection and precipitation over the southern Alps, leading to an expanded summer snow range and a lower equilibrium line altitude (ELA) of glaciers. The study also demonstrates the potential of the regional climate model for use in paleoclimate studies.
CLIMATE OF THE PAST
(2023)
Article
Geochemistry & Geophysics
Steve P. Lund, Martha Schwartz, Lloyd Keigwin
Summary: New paleomagnetic records recovered from deep-sea sediment cores of the Bahama Outer Ridge reveal the occurrence of the Blake Event around 119-126,000 years BP within Marine Isotope Stage 5. The Blake Event is characterized by a local magnetic field reversal and our detailed analysis confirms deviations from long-term averages on various timescales.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2021)
Article
Geography, Physical
Steve Lund, Ellen Platzman, Thomas C. Johnson
Summary: The study conducted paleomagnetic research on Holocene sediments from Lake Victoria to develop a high-resolution record of paleomagnetic secular variation. The results indicate that the PSV records are limited to the uppermost 5 meters of the cores due to significant magnetic mineral dissolution. By correlating PSV and rock magnetic/environmental measurements, the study provides a well-dated record of Holocene PSV for Africa, which can be compared with PSV records from Lake Malawi.
Article
Geochemistry & Geophysics
Marcel Bliedtner, Torsten Haberzettl, Norbert Nowaczyk, Enkhtuya Bazarradnaa, Roland Zech, Paul Strobel
Summary: Despite the inconsistency between paleomagnetic secular variations (PSV) and radiocarbon (C-14)-based lacustrine sediment chronologies at Khar Nuur in the Mongolian Altai Mountains, the inclination pattern at the site resembles regional and global geomagnetic field models with a constant offset of 730 +/- 90 years. The offset is not caused by reservoir effects or modern factors, but rather by the constant lock-in depth of 26 +/- 2 cm below the sediment-water interface at Khar Nuur. The good consistency in inclination further highlights the reliability of global geomagnetic field models in under-studied areas.
Article
Oceanography
Steve Lund, Makoto Okada, Emily Mortazavi
Summary: This study develops composite full-vector paleomagnetic secular variation (PSV) records from IODP Ex. 323 Sites U1339, U1343, U1344, and U1345 in the Bering Sea. These PSV records cover the last 71 ka (Marine Isotope Stages (MIS) 1-4) and provide important insights into the magnetic field behavior at high latitudes.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Geochemistry & Geophysics
A. Di Chiara, L. Tauxe, H. Staudigel, F. Florindo, M. Protti, Y. Yu, J. -A. Wartho, P. van den Bogaard, K. Hoernle
Summary: This study focused on the Cretaceous Normal Superchron (CNS) and found that the geomagnetic field strength was higher than the long-term average during this period, remaining consistent before and after the onset of CNS. This suggests that there is not a strict correlation between the length of polarity intervals and the strength of the magnetic field.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geosciences, Multidisciplinary
Andrea Magli, Stefano Branca, Fabio Speranza, Gilda Risica, Gaia Siravo, Guido Giordano
Summary: Determining the ages of past eruptions of active volcanoes is crucial for understanding the relationship between eruption phenomena and human settlements. This study used paleomagnetic measurements to investigate three lava flows in the urban district of Catania, finding that one of the flows may have buried Neolithic settlements.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
M. Pistolesi, M. Rosi, A. B. Malaguti, F. Lucchi, C. A. Tranne, F. Speranza, P. G. Albert, V. C. Smith, A. Di Roberto, E. Billotta
Summary: The study provides a detailed stratigraphy of pyroclastic successions and lava flows of the youngest volcanic eruptions in Lipari over the past 1500 years. By combining field observations, sedimentological characteristics, and geochemical compositions, the research offers a chronological framework for Lipari's volcanic activities and facilitates the correlation of rhyolitic tephra across the central Mediterranean region.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Arianna Beatrice Malaguti, Mauro Rosi, Marco Pistolesi, Fabio Speranza, Martin Menzies
Summary: This study presents a detailed reconstruction of the volcanic eruption history on the island of Vulcano, focusing on the period between the ninth and fifteenth centuries AD. By using a combination of tephrostratigraphy, standard palaeomagnetic methodology, and radiocarbon dating, the researchers were able to determine that the lavas exposed above sea level at Vulcanello were erupted between the tenth and eleventh century AD, rather than the previously suggested timeframe of the first and second century BC. The study also revealed that La Fossa caldera experienced at least 19 eruptions between the tenth and mid-sixteenth centuries, with an average eruption rate of one event every 34 years, suggesting a higher volcanic hazard at Vulcano than previously thought.
BULLETIN OF VOLCANOLOGY
(2022)
Article
Geosciences, Multidisciplinary
A. Todrani, F. Speranza, N. D'Agostino, B. Zhang
Summary: This study re-evaluates paleomagnetic datasets from Tibet-Indochina and compares them with present-day GPS velocity field. The results suggest that the rotation of the SE Tibet NW of the East Himalaya Syntaxis (EHS) occurred around 50 Ma, followed by clockwise rotations after 40 Ma. In the NE of EHS, clockwise rotations took place after 50 Ma, while scattered clockwise rotations occurred on northern Indochina at 25-15 Ma. These rotations were likely caused by the indentation of Greater India NE corner and local strike-slip fault activity.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Paolo Mancinelli, Vittorio Scisciani, Cristina Pauselli, Gerard M. Stampfli, Fabio Speranza, Ivana Vasiljevic
Summary: The study suggests that the geological features of the Central Adriatic Sea and surrounding areas are related to the Early Permian back-arc Adria continental breakup, and underplating during the Palaeotethys-Adria collision controlled topography and palaeogeographic domains. It is proposed that the Palaeotethys-Adria boundary in the Early Permian was similar to the current Pacific-Okhotsk plate boundary.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geography, Physical
L. Capraro, S. Bonomo, A. Di Stefano, P. Ferretti, E. Fornaciari, S. Galeotti, A. Incarbona, P. Macri, I Raffi, N. Sabatino, F. Speranza, M. Sprovieri, E. Di Stefano, R. Sprovieri, D. Rio
Summary: The Monte San Nicola area in southern Sicily provides a significant reference for the definition of the Gelasian Stage GSSP, and its importance has been reaffirmed. A comprehensive revision of the Gelasian Stage in its type area is needed to fully understand the evolution of bio- and magnetostratigraphic events.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
Gilda Risica, Alessio Di Roberto, Fabio Speranza, Paola Del Carlo, Massimo Pompilio, Stavros Meletlidis, Alessandro Todrani
Summary: This study reconstructs the timing of Holocene eruptions in El Hierro and finds uneven distribution of eruptions along three main rifts. The study identifies two periods of high eruption frequency, which are crucial for correctly assessing the volcanic hazard in the area.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2022)
Article
Geochemistry & Geophysics
Anita Di Chiara, F. Javier Pavon-Carrasco
Summary: Understanding the variations of the Earth's magnetic field over time in Africa is crucial for various reasons, including the study of the South Atlantic Anomaly (SAA) and the development of a regional geomagnetic model. The new model reveals the westward migration of the SAA from the Indian Ocean over Africa since 1100 CE and can be used for paleomagnetic dating of archaeological sites and volcanic units.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2022)
Article
Geochemistry & Geophysics
Gilda Risica, Mauro Rosi, Marco Pistolesi, Fabio Speranza, Michael J. Branney
Summary: This article examines the impact of hazardous pyroclastic density currents (PDCs) and suggests that the mass flux of a PDC may derive not only from vent discharge during eruption, but also from temporary stores of aerated pyroclastic material on the volcano. The study analyzes a PDC event at Fuego volcano in Guatemala and reveals that the majority of the PDC originated from loose and partly hot pyroclastic deposits stored high on the volcano over the past 2-3 years. The findings emphasize the importance of considering deposit-derived pyroclastic currents in hazard assessment and monitoring.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Gaia Siravo, Fabio Speranza, Patrizia Macri
Summary: This study investigates the paleomagnetism of the Calabrian block and reveals evidence of a approximately 160-degree counterclockwise rotation of the block with respect to Europe. Additionally, a approximately 20-degree clockwise rotation during the Pleistocene period is also identified. The study suggests a potential approximately 70-degree counterclockwise rotation of the Calabrian block during the Cretaceous-Eocene period.
Article
Geosciences, Multidisciplinary
Arianna Beatrice Malaguti, Stefano Branca, Fabio Speranza, Mauro Coltelli, Paola Del Carlo, Alberto Renzulli
Summary: This study provides the first age constraints on the Milo debris avalanche deposit and the overlying lava succession in the Valle del Bove on Mount Etna. The results indicate that the catastrophic flank collapse of the Valle del Bove occurred during the Mesolithic age, while the main lava emplacement took place during the Late Copper age. Paleomagnetic dating also reveals the occurrence of quasi-contemporaneous flank eruptions during different historical periods. These findings have important implications for the stratigraphy and evolution of Mount Etna.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2023)
Article
Geochemistry & Geophysics
Gaia Siravo, Fabio Speranza, Massimo Mattei
Summary: It has been discovered that the Corsica-Sardinia microplate rotated counterclockwise by 40-50 degrees between 21 and 15 Ma, in conjunction with Liguro-Provencal Basin oceanic spreading. Conversely, rotations of 60-120 degrees counterclockwise with respect to Europe have been observed in Sardinia, and these rotations are believed to be related to events such as late Permian shear events, Aptian Iberia rotation, and Eocene Valais Ocean closure. Recent paleomagnetic data suggests that Sardinia was part of Iberia and experienced counterclockwise rotations during both Aptian Iberia drift and Oligo-Miocene Liguro-Provencal opening.
Article
Geochemistry & Geophysics
Anita Di Chiara, Adrian R. Muxworthy, Ricrdo I. F. Trindade, Franklin Bispo-Santos, Evelyn B. Baker
Summary: Palaeointensity data from the Precambrian are crucial for understanding the timing of Inner Core Nucleation (ICN), but limited data has made it difficult to determine its timing. Numerical dynamo simulation models predict an increase in entropy, affecting the field strength and showing an anomaly in the palaeointensity record at ICN. New estimates of geomagnetic field intensity from the Mid-Mesoproterozoic Nova Guarita dyke swarm provide valuable constraints for assessing numerical simulations of the Mesoproterozoic geodynamo.
STUDIA GEOPHYSICA ET GEODAETICA
(2023)
Article
Geochemistry & Geophysics
A. Scarani, C. F. Faranda, A. Vona, F. Speranza, G. Giordano, S. G. Rotolo, C. Romano
Summary: We used Differential Scanning Calorimetry, paleomagnetic analysis, and numerical modeling to study the timescales of ductile deformation in the Green Tuff ignimbrite. By measuring glass fictive temperatures and conducting paleomagnetic analyses, we determined cooling rates and emplacement temperatures of the ignimbrite. Our findings suggest intense syn-depositional ductile deformation in the upper and basal vitrophyres, and post-emplacement rheomorphic flow in the central body. Shear heating and retrograde solubility of volatiles play a critical role in controlling the rheological behavior of the ignimbrite.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)