Publications
Filter Total Items: 7494
Close temporal correspondence between geomagnetic anomalies and earthquakes during the 2002-2003 eruption of Etna volcano Close temporal correspondence between geomagnetic anomalies and earthquakes during the 2002-2003 eruption of Etna volcano
The early stages of the 2002-2003 lateral eruption at Mount Etna were accompanied by slow changes (over some hours) and some rapid step offsets in the local magnetic field. At five monitoring locations, the total magnetic field intensity has been measured using continuously operating Overhauser magnetometers at a sampling rate of 10 s. The very unique aspect of these observations is the...
Authors
G. Currenti, Negro C. Del, M. Johnston, Y. Sasai
Paleoenvironmental assessment of recent environmental changes in Florida Bay, USA: a biomarker based study Paleoenvironmental assessment of recent environmental changes in Florida Bay, USA: a biomarker based study
The extractable lipid compositions in four Florida Bay cores were determined in order to understand environmental changes over the last 160 years. The most significant environmental change was recorded by oscillations in the amplitude and frequency of biomarkers during the 20th century. Two seagrass molecular proxies (Paq and the C25/C27n-alkan-2-one ratio) reached a maximum post 1900...
Authors
Y. Xu, C. W. Holmes, R. Jaffe
A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary A multiple-approach radiometric age estimate for the Rotoiti and Earthquake Flat eruptions, New Zealand, with implications for the MIS 4/3 boundary
Pyroclastic fall deposits of the paired Rotoiti and Earthquake Flat eruptions from the Taupo Volcanic Zone (New Zealand) combine to form a widespread isochronous horizon over much of northern New Zealand and the southwest Pacific. This horizon is important for correlating climatic and environmental changes during the Last Glacial period, but has been the subject of numerous disparate age...
Authors
C. J. N. Wilson, D.A. Rhoades, M. A. Lanphere, A.T. Calvert, Bruce F. Houghton, S.D. Weaver, J. W. Cole
Interferogram formation in the presence of complex and large deformation Interferogram formation in the presence of complex and large deformation
Sierra Negra volcano in Isabela island, Galápagos, erupted from October 22 to October 30 in 2005. During the 8 days of eruption, the center of Sierra Negra's caldera subsided about 5.4 meters. Three hours prior to the onset of the eruption, an earthquake (Mw 5.4) occurred, near the caldera. Because of the large and complex phase gradient due to the huge subsidence and the earthquake, it...
Authors
S.-H. Yun, H. Zebker, P. Segall, A. Hooper, Michael P. Poland
Characteristics of vesicomyid clams and their environment at the Blake Ridge cold seep, South Carolina, USA Characteristics of vesicomyid clams and their environment at the Blake Ridge cold seep, South Carolina, USA
Spatial distributions and patchiness of dominant megafaunal invertebrates in deep-sea seep environments may indicate heterogeneities in the flux of reduced chemical compounds. At the Blake Ridge seep off South Carolina, USA, the invertebrate assemblage includes dense populations of live vesicomyid clams (an undescribed species) as well as extensive clam shell beds (i.e. dead clams). In...
Authors
Taylor P. Heyl, William P. Gilhooly, Randolph M. Chambers, George W. Gilchrist, Stephen A. Macko, Carolyn D. Ruppel, Cindy L. Van Dover
Strombolian explosive styles and source conditions Strombolian explosive styles and source conditions
Forward Looking Infrared Radiometer (FLIR) cameras offer a unique view of explosive volcanism by providing an image of calibrated temperatures. In this study, 344 eruptive events at Stromboli volcano, Italy, were imaged in 2001–2004 with a FLIR camera operating at up to 30 Hz. The FLIR was effective at revealing both ash plumes and coarse ballistic scoria, and a wide range of eruption...
Authors
Matthew R. Patrick, Andrew J. L. Harris, Maurizio Ripepe, Jonathan Dehn, David A. Rothery, Sonia Calvari
Volcano-electromagnetic effects Volcano-electromagnetic effects
Volcano-electromagnetic effects—electromagnetic (EM) signals generated by volcanic activity—derive from a variety of physical processes. These include piezomagnetic effects, electrokinetic effects, fluid vaporization, thermal demagnetization/remagnetization, resistivity changes, thermochemical effects, magnetohydrodynamic effects, and blast-excited traveling ionospheric disturbances...
Authors
Malcolm J. S. Johnston
Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption
The May 18, 1980 Mount St. Helens eruption perturbed the atmosphere and generated atmosphere-to-ground coupled airwaves, which were recorded on at least 35 seismometers operated by the Pacific Northwest Seismograph Network (PNSN). From 102 distinct travel time picks we identify coherent airwaves crossing Washington State primarily to the north and east of the volcano. The travel time...
Authors
J.B. Johnson, S. D. Malone
The health hazards of volcanic ash--A guide for the public The health hazards of volcanic ash--A guide for the public
This document has been prepared by the International Volcanic Health Hazard Network (IVHHN), Cities and Volcanoes Commission, GNS Science and the United States Geological Survey (USGS) to promote the safety of those who experience volcanic ashfall. This guide explains the potential health effects of volcanic ash and gives details on how to protect yourself and your family in the event of...
Authors
C. Horwell, P. Baxter
Guidelines on preparedness before, during, and after an ashfall Guidelines on preparedness before, during, and after an ashfall
This document has been prepared by the International Volcanic Health Hazard Network (IVHHN), Cities and Volcanoes Commission, GNS Science and the United States Geological Survey (USGS) to promote the safety of those who experience volcanic ashfall. It details procedures to follow if warning of a volcanic ashfall is given, recommends what to do during ashfall, and what methods are most...
Authors
C. Horwell
Seismo-acoustic signals associated with degassing explosions recorded at Shishaldin Volcano, Alaska, 2003-2004 Seismo-acoustic signals associated with degassing explosions recorded at Shishaldin Volcano, Alaska, 2003-2004
In summer 2003, a Chaparral Model 2 microphone was deployed at Shishaldin Volcano, Aleutian Islands, Alaska. The pressure sensor was co-located with a short-period seismometer on the volcano’s north flank at a distance of 6.62 km from the active summit vent. The seismo-acoustic data exhibit a correlation between impulsive acoustic signals (1–2 Pa) and long-period (LP, 1–2 Hz) earthquakes...
Authors
T. Petersen
Precursory seismicity associated with frequent, large ice avalanches on Iliamna Volcano, Alaska, USA Precursory seismicity associated with frequent, large ice avalanches on Iliamna Volcano, Alaska, USA
Since 1994, at least six major (volume>106 m3) ice and rock avalanches have occurred on Iliamna volcano, Alaska, USA. Each of the avalanches was preceded by up to 2 hours of seismicity believed to represent the initial stages of failure. Each seismic sequence begins with a series of repeating earthquakes thought to represent slip on an ice-rock interface, or between layers of ice. This...
Authors
Jacqueline Caplan-Auerbach, C. Huggel