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Results for “GNS Science Report”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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8 recordsLinked to original sources
USGS2021

Mass eruption rate, column height, and duration dataset for volcanic eruptions

This report describes a dataset assembled and curated as part of a project funded by the Earthquake Commission Biennial Grant 20781, Towards real-time probabilistic ash deposition forecasting for Aotearoa New Zealand. This dataset compiles measured, estimated, and calculated values for volcanic eruption mass eruption rates, column heights, and durations. Data comes from 213 eruptions, with about a third from New Zealand volcanoes. 65% of eruptions have a value for all three parameters. Eruptions are further classified according to magma and eruption type to prepare for further analysis. This dataset will be used to develop prior probability density functions (PDFs) for mass eruption rate (MER), column height, and duration to quantify uncertainty in volcanological inputs with the aim of production of real-time probabilistic ashfall forecasts.

GNS Science Report↗
USGS2019

Impacts of the 2015 eruption of Calbuco volcano on Chilean infrastructure, utilities, agriculture, and health

This report presents data and summarises the findings of a reconnaissance trip investigating the impacts of the April 2015 eruption of Calbuco volcano, Chile, undertaken in November-December 2016. This study is mostly focused on the Los Lagos region, focusing on impacts occurring within ~30 km of the volcano, which includes the tourism town of Puerto Varas and port city of Puerto Montt. Eruption impacts and response strategies may be similar for moderate size eruptions from other stratovolcanoes in temperate regions. As such, this study provides useful information for development of contingency plans at active volcanoes around the world. The 2015 eruption of Calbuco volcano began at 18:04 (local time) on 22 April 2015 and consisted of three eruptive phases. The first lasted for 1.5 hours and generated a 15-km eruption column and plume that was directed towards the northeast. Pyroclastic density currents (PDCs) were generated locally and distributed radially, affecting many of the major rivers. A second phase began at 01:00 (local time) on 23 April 2015, lasted six hours and generated a 17-km high eruption column and plume that was dispersed towards the north-northeast, and the most voluminous pyroclastic density currents of the sequence. A third eruptive phase occurred on 30 April 12:10 (local time) resulting in a 5-km column and plume dispersed towards the east.

Calbuco volcano↗
USGS2014

Rapid earthquake characterization using MEMS accelerometers and volunteer hosts following the M 7.2 Darfield, New Zealand, Earthquake

We test the feasibility of rapidly detecting and characterizing earthquakes with the Quake‐Catcher Network (QCN) that connects low‐cost microelectromechanical systems accelerometers to a network of volunteer‐owned, Internet‐connected computers. Following the 3 September 2010 M 7.2 Darfield, New Zealand, earthquake we installed over 180 QCN sensors in the Christchurch region to record the aftershock sequence. The sensors are monitored continuously by the host computer and send trigger reports to the central server. The central server correlates incoming triggers to detect when an earthquake has occurred. The location and magnitude are then rapidly estimated from a minimal set of received ground‐motion parameters. Full seismic time series are typically not retrieved for tens of minutes or even hours after an event. We benchmark the QCN real‐time detection performance against the GNS Science GeoNet earthquake catalog. Under normal network operations, QCN detects and characterizes earthquakes within 9.1 s of the earthquake rupture and determines the magnitude within 1 magnitude unit of that reported in the GNS catalog for 90% of the detections.

Darfield↗
USGS2015

Improved rapid magnitude estimation for a community-based, low-cost MEMS accelerometer network

Immediately following the M w 7.2 Darfield, New Zealand, earthquake, over 180 Quake‐Catcher Network (QCN) low‐cost micro‐electro‐mechanical systems accelerometers were deployed in the Canterbury region. Using data recorded by this dense network from 2010 to 2013, we significantly improved the QCN rapid magnitude estimation relationship. The previous scaling relationship ( Lawrence et al. , 2014 ) did not accurately estimate the magnitudes of nearby (<35 km) events. The new scaling relationship estimates earthquake magnitudes within 1 magnitude unit of the GNS Science GeoNet earthquake catalog magnitudes for 99% of the events tested, within 0.5 magnitude units for 90% of the events, and within 0.25 magnitude units for 57% of the events. These magnitudes are reliably estimated within 3 s of the initial trigger recorded on at least seven stations. In this report, we present the methods used to calculate a new scaling relationship and demonstrate the accuracy of the revised magnitude estimates using a program that is able to retrospectively estimate event magnitudes using archived data.

Bulletin of the Seismological Society of America↗
USGS2007

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 a volcanic ashfall.

Report↗
USGS2007

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 effective for cleaning up volcanic ash after the event.

Report↗
USGS2018

Overview of the geologic effects of the November 14, 2016, Mw 7.8 Kaikoura, New Zealand, earthquake

The November 14, 2016, Kaikoura, New Zealand, earthquake (moment magnitude [Mw] 7.8) triggered more than 10,000 landslides over an area of about 12,000 square kilometers in the northeastern part of the South Island of New Zealand. In collaboration with GNS Science (the Institute of Geological and Nuclear Science Limited), we conducted ground and helicopter reconnaissance of the affected areas and assisted in rapid hazard evaluation. The majority of the triggered landslides were shallow- to moderate-depth (1–10 meters), highly disrupted falls and slides in rock and debris from Lower Cretaceous graywacke sandstone in the Seaward Kaikoura Range. Deeper, more coherent landslides in weak Upper Cretaceous to Neogene sedimentary rock also were numerous in the gentler topography south and inland (west) of the Seaward Kaikoura Range. The principal ground-failure hazards from the earthquake were the hundreds of valley-blocking landslides, many of which impounded lakes and ponds that posed potential downstream flooding hazards. Both large and small landslides also blocked road and rail corridors in many locations, including the main north-south highway (State Highway 1), which was still closed in October 2017. As part of our investigation, we compared post-earthquake field observations to the output of models used to estimate near-real-time landslide probabilities following earthquakes. The models generally over-predicted landslide occurrence and thus need further refinement.

Kaikoura↗
USGS2026

Determining Volcanic Risk in Auckland (DEVORA) Research Programme—A transdisciplinary approach to address the challenge of distributed volcanism in an urban environment

The Determining Volcanic Risk in Auckland (DEVORA) Research Programme was launched in 2008 to address the challenges associated with monogenetic volcanism in an urban setting and to enhance volcanic risk management in Tāmaki Makaurau Auckland in Aotearoa New Zealand. It is a multi-agency, increasingly transdisciplinary (defined here as research that transcends traditional disciplinary boundaries by integrating diverse types of knowledge, perspectives, and methods from academic and non-academic participants to create novel solutions to complex problems), and collaborative research program jointly led by Waipapa Taumata Rau University of Auckland and Earth Sciences New Zealand (ESNZ; formerly GNS Science), with core funding from Natural Hazards Commission Toka Tū Ake (NHC; formerly the Earthquake Commission, EQC) and Te Kaunihera o Tāmaki Makaurau Auckland Council (AC). The primary research focus of DEVORA is to investigate the geologic history, volcanic hazards, and risk posed by the basaltic intraplate Auckland Volcanic Field. Disruption from ash fall and gas from other Aotearoa New Zealand volcanoes is also considered. DEVORA’s work to explore exposure and vulnerability in Tāmaki Makaurau Auckland is also useful for assessing risks from other non-volcanic natural hazards, such as seismic and tsunami hazards. The greater Tāmaki Makaurau Auckland region has an ethnically and socio-economically diverse population of approximately 1.7 million, representing about one-third of the Aotearoa New Zealand population, and hosts critical infrastructure of national significance. The size and nature of the populace, consequential economic base, and important infrastructure within Tāmaki Makaurau Auckland mean that the effects of a volcanic eruption would be felt nationally, including through the disruption of air travel to Aotearoa New Zealand. The hazards from such an eruption could potentially affect hundreds of thousands of people, businesses, and lifelines (critical infrastructure). A considerable challenge for emergency and risk managers is the monogenetic nature of the volcanic field. It is not known where or when the next eruption will occur, how much warning we may get before an eruption, nor how an eruption and its effects might unfold. In this contribution, we highlight the concept and collaborative intent of the DEVORA Programme and show how it has evolved over the 16 years since its inception. We describe how DEVORA has unified more than 100 researchers (including more than 50 graduate students) and numerous stakeholders to address key issues facing Tāmaki Makaurau Auckland and describe how research findings are being implemented into policy and communicated to stakeholder agencies and the public. We also illustrate the broader influence of the DEVORA Programme and provide some learnings that might benefit others embarking on similar integrated projects, especially those focused on distributed volcanism in and near populated areas.

Auckland↗