Elske De Zeeuw-van Dalfsen

Koninklijk Nederlands Meteorologisch Instituut | KNMI · Seimology and Acoustics

Volcano Observatories (VOs) around the world are required to maintain surveillance of their volcanoes and inform civil protection and aviation authorities about impending eruptions. They often work through consolidated procedures to respond to volcanic crises in a timely manner and provide a service to the community aimed at reducing the potential...

The seismic network NA (Caribbean Netherlands Seismic Network) in the Caribbean Netherlands is deployed by the Royal Netherlands Meteorological Institute (KNMI) to monitor local seismicity around Saba, St. Eustatius, and St. Maarten, and to contribute data to regional earthquake and tsunami warning monitoring systems. The network currently comprise...

Over the first century of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI), volcano geodesy grew from roots as an accidental and incidental system of measurements to an important method for monitoring volcanic activity and forecasting eruptions. The first practitioners in volcano geodesy were experts in ot...

Results from nine microgravity campaigns from Kı̄lauea, Hawaiʻi, spanning most of the volcano's 2008–2018 summit eruption, indicate persistent mass accumulation at shallow levels. A weighted least squares approach is used to recover microgravity results from a network of benchmarks around Kı̄lauea's summit, eliminate instrumental drift, and restore...

We use ground and space geodetic data to study surface deformation at Kīlauea Volcano from January to September 2015. This period includes an episode of heightened activity in April and May 2015 that culminated in a magmatic intrusion beneath the volcano's summit. The data set consists of Global Navigation Satellite System (GNSS), tilt, visual and...

Since the beginning of the 20th century, volcano geodesy has evolved from time- and personnel-intensive methods for collecting discrete measurements to automated and/or remote tools that provide data with exceptional spatiotemporal resolution. By acknowledging and overcoming limitations related to data collection and interpretation, geodesy becomes...

Knowledge of the spatio-temporal changes in the characteristics and distribution of subsurface fluids is key to properly addressing important societal issues, including: sustainable management of energy resources (e.g., hydrocarbons and geothermal energy), management of water resources, and assessment of hazard (e.g., volcanic eruptions). Gravimetr...

The continuous recordings of broadband seismometers on Saba and St. Eustatius in the Lesser Antilles provide a unique and long data set to measure temporal seismic velocity variations (dv/v) at two active but quiescent volcanoes (Mt. Scenery and The Quill). We compare results from single-station cross-component (SC) correlations with cross-station...

Volcanic activity is always accompanied by the transfer of heat from the Earth’s crust to the atmosphere. This heat can be measured from space and its measurement is a very useful tool for detecting volcanic activity on a global scale. MIROVA (Middle Infrared Observation of Volcanic Activity) is an automatic volcano hot spot detection system, based...

We conducted gravity surveys of the summit area of Kīlauea Volcano, Hawaiʻi, in November 2018 and March 2019, with the goal of determining whether there was any mass change at depth following the volcano's May–August 2018 caldera collapse. Surface deformation between the two surveys was minimal, but we measured a gravity increase (maximum 44 μGal)...

Microgravity time series at active volcanoes can provide an indication of mass change related to subsurface magmatic processes, but uncertainty is often introduced by hydrologic variations and other noise sources that cannot easily be isolated. We empirically assessed seasonality and noise by conducting four surveys over the course of May–October 2...

The stratovolcanoes of Mt. Scenery at Saba and The Quill in St. Eustatius in the Caribbean Netherlands, with a total population of about 5200 people, are part of the active volcanic arc of the Lesser Antilles but lacked a multiparameter volcano and earthquake monitoring system until the beginning of 2018. The permanent seismic network on the island...

Small-scale geomorphological changes that are associated with the formation, development, and activity of volcanic craters and eruptive vents are often challenging to characterize, as they may occur slowly over time, can be spatially localized, and difficult, or dangerous, to access. Using high-spatial and high-temporal resolution synthetic apertur...

The volcanoes of the Quill (St. Eustatius) and Mt. Scenery (Saba) are part of the Lesser Antilles volcanic island arc in the West Indies, which hosts seventeen active volcanoes. The last eruptive activity at the Quill occurred 1600-1800 years ago but Mt. Scenery erupted as recent as in 1640. The existence of heated groundwater at St. Eustatius and...

Lava flow simulations help to better understand volcanic hazards and may assist emergency preparedness at active volcanoes. We demonstrate that at Fogo Volcano, Cabo Verde, such simulations can explain the 2014–2015 lava flow crisis and therefore provide a valuable base to better prepare for the next inevitable eruption. We conducted topographic ma...

Lava flow simulations help to better understand volcanic hazards and may assist emergency preparedness at active volcanoes. We show that at Fogo Volcano, Cape Verde, such simulations can explain the 2014–2015 lava flow crisis and therefore provide a valuable base to better prepare for the inevitable next eruption. In a rapid disaster response effor...

content: "The structural development of the nested summit craters of Láscar volcano studied with a Terrestrial Laser Scanner." Láscar volcano is the most active volcano of the Central Volcanic Zone in the Chilean Andes. The 5600 m high composite stratocone hosts five NNE-SSW trending summit craters that are partially overlapping (nested). The two c...

content: Lava flow morphology and dynamics during the 2014/2015 Fogo eruption, studied using Terrestrial Laser Scanner data Fogo Volcano is the only historically active volcano of the Cabo Verde Islands. Pico do Fogo stratocone (2829 m), the most prominent feature within " Chá das Caldeiras " (Chá), started a flank eruption on the 23rd of November...

After 20 years of quiescence, Fogo volcano (Cape Verdes) initiated an eruption on 23 November 2014. The eruption had significant precursors, such as degassing and seismicity, and occurred at a similar location as in 1995. Lava flows rapidly propagated to inhabited regions, a significant part of the Islands' population has been replaced in the towns...

Popocatepetl is an active 5426 m high stratovolcano, with a steep-walled, 400 by 600 m wide crater. It is located 70 km southeast of Mexico city, and its activity potentially influences up to 25 million people. More than 15 major eruptions occurred in historic times, the last one in 1947. The year 2012 has been a highly active one, with numerous as...

Many calderas in the world show long-term unrest in the form of elevated rates of deformation and seismicity, related to pressure changes and magma movements within their magmatic plumbing systems. We present new observations of the style of deformation at the Askja caldera, Iceland, since 2000, using interferometric analysis of synthetic aperture...

Iceland is the only sub-aerial exposure of the mid-Atlantic ridge on Earth, and is an ideal place to study the mechanics and dynamics of magma ascent related to plate spreading processes. We focus on the Northern Volcanic Zone (NVZ) - an extensional rift segment bounded to the south by the Icelandic mantle plume, currently beneath the Vatnajökull i...

The Askja Volcanic center, in the Northern Volcanic Zone in Iceland, hosts 3 calderas. The main, Askja caldera has been deflating at least since 1983 and probably even since 1973. The last eruption at Askja took place in 1961 when an 800 m long fissure opened along the northern part of the caldera. Here, we present a comparison of precise levelling...

We have used RADARSAT SLC images from the Canadian Space Agency to create complex interferograms from part of the northern volcanic zone in Iceland. The dataset covers the 2000-2009 period and is a valuable addition to the limited number of good interferometric image pairs available for the area during this time, due to problems with the ERS in 200...

The Krafla rifting episode, 1975-1984, was followed by inflation of a shallow magma chamber until 1989. At that time, subsidence began above the magma chamber and has continued to date. Other sources of deformation have been observed at Krafla. Plate spreading as well as deformation processes due to utilization at two geothermal fields, is evident...

New and previously published micro-gravity data are combined with InSAR data, precise levelling and GPS measurements to produce a model for the processes operating at Krafla volcano, 20 years after its most recent eruption. The data have been divided into two periods: from 1990 to 1995 and from 1996 to 2003 and show that the rate of deflation at Kr...

Here we review the achievements of volcano geodesy in Iceland during the last 15 years. Extensive measurements of crustal deformation have been conducted using a variety of geodetic techniques, including leveling, electronic distance measurements, campaign and continuous Global Positioning System (GPS) geodesy, and interferometric analysis of synth...

Askja caldera in northeast Iceland has been in a state of unrest for decades. Ground-deformation surveys show that the rate of deformation, i.e., deflation, is much higher then observed at any other dormant volcano in Iceland. This work presents the results from microgravity and deformation studies at Askja from 1988 to 2003. The deflation reaches...

Crustal deformation events in Iceland in a variety of tectonic settings have been recognized using ERS1 and ERS2 images provided by ESA, including: (1) Intrusions in the Eyjafjallajökull volcanic system. Images spanning 1993-2000 identify considerable surface deformation in an area south of the Eyjafjallajökull icecap. The intrusive events (occurri...

Deep magma accumulation near the crust-mantle boundary (21 km depth) at the Krafla volcanic system is suggested from InSAR observations. A best fit model, derived from four interferograms covering 1993-1999, comprises an opening dike, representing plate spreading and post-rifting deformation, and two Mogi sources. A Mogi source deflating at a rate...