hein haak | University of Groningen (original) (raw)

Papers by hein haak

At the previous International Lightning Detection Conference (ILDC 2004) in Helsinki, Beekhuis an... more At the previous International Lightning Detection Conference (ILDC 2004) in Helsinki, Beekhuis and Holleman (2004) presented the upgrade and evaluation of the KNMI lightning detection system. Since 1995 KNMI operates a SAFIR (Surveillance et Alerte Foudre par Interferometrie Radioelectrique) Lightning Detection System for monitoring (severe) convection and for feeding a climatological database. In 2003 the lightning detection stations and the central processor (application and hardware) have been replaced.

66th EAGE Conference & Exhibition, 2004

P193 EXPERIMENTAL RESULTS FOR DESIGNING SEISMIC MONITORING NETWORKS ON LAND Summary 1 As part of ... more P193 EXPERIMENTAL RESULTS FOR DESIGNING SEISMIC MONITORING NETWORKS ON LAND Summary 1 As part of a project to set up a seismic monitoring network in the Netherlands passive and active experiments have been performed to investigate the influence of receiver parameters on the signal-to-noise ratio and the resolution. The parameters that have been investigated mostly experimentally are: depths of geophones and array-configurations of geophones. One particular goal was to find out whether it would be advantageous to use a sparse array at depth or a dense array at or near the surface. The main result following from the experiments is

Netherlands Journal of Geosciences - Geologie en Mijnbouw, 2001

The province of Groningen is flat and level, lying at an elevation close to sea level. The area i... more The province of Groningen is flat and level, lying at an elevation close to sea level. The area is intensely cultivated and water table levels are a matter of concern. When the size of the Groningen gasfield was recognized in the sixties, it was realized, that substantial subsidence might occur at the surface affecting a large area.Intensive studies were performed over time to predict future subsidence. These studies are supported by theoretical and experimental research in Shell since the 1950’s concerning reservoir compaction and related surface subsidence. To monitor reservoir compaction and surface subsidence on a regular basis, an extensive monitoring program was set up by NAM. The program comprises leveling surveys, GPS measurements, measurements of shallow formation compaction and in-situ reservoir compaction.In Groningen weak earthquakes have occurred since 1991 at irregular intervals. A multidisciplinary study from 1991–1993 on the relationship between gas production and ea...

ABSTRACT A small scale experiment with borehole tiltmeters above a gasfield in the Netherlands is... more ABSTRACT A small scale experiment with borehole tiltmeters above a gasfield in the Netherlands is described. Pressure variations in the gasfield may cause subsurface deformations leading to tilt. We describe the technique of the installation of the tiltmeters and the influence of the surface conditions on the measurements. For this case study we quantify the minimum pressure variation which is required to result in observable, induced tilt. Tidal tilt observations are shown and used for the verification of the measurements. Finally, we compare the observations with computed ocean tide loading tilt for the M2 tidal component.

Introduction • In New York on 24 September 1996 President Clinton was the first head of state to ... more Introduction • In New York on 24 September 1996 President Clinton was the first head of state to sign the Comprehensive Nuclear-Test-Ban Treaty (ctbt) on behalf of the United States of America. This signature was a milestone in a period of just over 50 years since the first nuclear test in July 1945, called Trinity, and the subsequent development and testing of nuclear weapons. In this 50-year period over 2000 nuclear tests have been conducted.

The Netherlands has large on-land gas reservoirs, which are being exploited since 1960. Small-mag... more The Netherlands has large on-land gas reservoirs, which are being exploited since 1960. Small-magnitude (ML ≤ 3.5), shallow (depth < 4 km) events induced by this gas exploitation cause light damage and much concern to the regional population. As one of the consequences the Dutch law requires since 2003 seismic hazard and risk estimates for each mining concession. Up to now only general quantitative hazard estimates, maximum possible earthquake and maximum possible intensity were available. Here we provide more specific quantitative hazard estimates. A long-term monitoring program shows a stationary rate of seismicity since 1992, probably coupled to a stationary production rate. Based on this we present a first order sitespecific hazard estimate using a Probablistic Seismic Hazard Analysis (PSHA). We predict, and observe, relatively high Peak Ground Accelerations (PGA). PGA above 0.2g is not unusual, but damage has so far been restricted to non-structural damage, mainly cracks in ...

Eos, Transactions American Geophysical Union, 2010

... At KNMI Laslo Evers, Bernard Dost and Ko van Gend supplied figures, and Marieke Laagland is t... more ... At KNMI Laslo Evers, Bernard Dost and Ko van Gend supplied figures, and Marieke Laagland is thanked for reformatting and correcting all the text. ... Stockholm, Sweden Kjeller, Norway De Bilt, The Netherlands Ola Dahlman Svein Mykkeltveit Hein Haak Page 12. ...

Low Frequency Noise & Vibration and Active Control, 2000

The Seismology Division of the Royal Netherlands Meteorological Institute (KNMI) has built up exp... more The Seismology Division of the Royal Netherlands Meteorological Institute (KNMI) has built up expertise in infrasound measurements by investigating low frequency events in order to distinguish between seismic and sonic events. KNMI operates, amongst others, a sixteen element microbarometer array with an aperture of 1.5 km, the Deelen Infrasound Array (DIA). Sonic booms and events of Comprehensive Test Ban Treaty (CTBT) interest are detected and identified within the frequency range of 500 seconds up to 40 Hertz. Recently, KNMI and Microflown Technologies B.V. started a collaboration concerning infrasound measurements. This paper reports on the use of a novel sensor. The so-called Microflown[1] is a micro-machined particle velocity sensor, sensitive to frequencies from 0Hz up to at least 1kHz. Experiments with the Microflown for infrasound detection show promising results.

Bollettino Di Geofisica Teorica Ed Applicata, 2004

Measured accelerations caused by induced and tectonic events in the Netherlands have been made av... more Measured accelerations caused by induced and tectonic events in the Netherlands have been made available since 1997. Measured mean horizontal peak ground accelerations reach values of up to 2.2 m/s 2 for an induced event of magnitude 3.4 at a hypocentral distance of 2.5 km and with a dominant frequency of 10 Hz. Measured mean peak horizontal ground velocities reach values of up to 4.5 cm/s for a tectonic event of magnitude 3.9 at a hypocentral distance of 4.4 km. These high values are predicted by existing empirical relations for the scaling of peak ground acceleration and peak ground velocity. The best fit for the observations of magnitudes larger than 3.0, taking into account that underestimates should be avoided, is given by Campbell (1997). For the total magnitude range, a new scaling relation for the Netherlands was estimated, based on the attenuation relation determined to calculate local magnitudes for induced events. These relations will be used in updates of seismic hazard ...

Monitoring of infrasound has been widely applied in the past to detect nuclear tests. The Limited... more Monitoring of infrasound has been widely applied in the past to detect nuclear tests. The Limited (Partial) Test Ban Treaty of 1963 confined nuclear test explosions to the underground marking the end of the global interest in infrasound. During the negotiation of the Comprehensive Nuclear-Test-Ban Treaty, in 1995-96, it became gradually clear that infrasound monitoring should be become one of the four techniques for the treaty’s verification system. The global interest in infrasound has increased significantly since the signature of the CTBT. Meteors are one of the few natural sources mimicking a nuclear. Therefore, it is an ideal object to test detection capability, phase identifiers, localization procedures and propagation models of infrasound and their processing techniques. In this presentation, we will show the results of studies on meteoric-generated infrasound and their implications for infrasound as verification technique. In addition, results of the 2007.09.15 meteor in Per...

Bulletin of the Seismological Society of America, 2006

ABSTRACT

Physical Review Letters, 1978

We demonstrate the feasibility of Auger-photoelectron coincidence spectroscopy (APECS) and use th... more We demonstrate the feasibility of Auger-photoelectron coincidence spectroscopy (APECS) and use this technique to study the Cu L 23 M 45 M 45 Auger transitions. With APECS the Auger lines can be identified unambiguously and the Coster-Kronig-preceded Auger lines ...

Het IPCC brengt verspreid over 2007 in vier delen het vierde klimaatrapport uit (Fourth Assessmen... more Het IPCC brengt verspreid over 2007 in vier delen het vierde klimaatrapport uit (Fourth Assessment Report - AR4). Het geeft daarmee de nieuwste inzichten op het gebied van klimaatverandering in de wereld. Aan het AR4 hebben honderden gerenommeerde klimaatonderzoekers uit de hele wereld meegewerkt, waaronder verschillende uit Nederland. De hoofdrapporten met de wetenschappelijke onderbouwing komen dit jaar stapsgewijs beschikbaar. Eind november volgt het zogeheten ‘synthesis report’ van het IPCC. In dit rapport zullen de bevindingen en conclusies van de drie werkgroeprapporten in samenhang beschouwd worden om zo een integraal wetenschappelijk beeld te geven van ons huidige begrip van klimaatverandering. Deze stand van zaken rond klimaatverandering en Nederland wordt gegeven door: MNP, KNMI, VU Amsterdam, Universiteit Utrecht, NWO, Wageningen UR en ECN

Nuclear Test Ban By Ola Dahlman Svein Mykkeltveit and Hein Haak Berlin Springer 2009 Isbn 978 1 4020 6883 6, 2009

Bulletin of the Atomic Scientists, 2002