Exploring the Development of GICs Related to Large dB/dt Variations in Space
1University of Alberta, Canada; 2NASA Goddard Space Flight Center, Greenbelt, Maryland, USA; 3Mullard Space Science Laboratory, University College London, Dorking, UK; 4Space Science Institute, Boulder, Colorado, USA
Geomagnetically induced currents (GICs) can be driven in terrestrial electrical power grids as a result of the induced electric fields arising from magnetic field changes driven in the coupled magnetosphere-ionosphere-ground system. Substorms are often hypothesised to be associated with the largest GIC effects on the ground, especially at higher latitudes. However, recent studies have suggested that other dayside phenomena such as sudden impulses and even ULF wave trains might also drive significant GICs. To investigate the evolution of magnetospheric disturbances, ionospheric currents, and their associated GICs, we have searched for conjugate magnetometer measurements from the GOES East and West, Swarm, and e-POP satellites, and the CARISMA ground array. We have focused on large dB/dt events, since ground dB/dt can be used as a GIC proxy. Several such events in space have been found with dB/dt of the order of hundreds of nT in the span of a only a few seconds. These are observed in both the nightside and dayside, and, as such, we seek to establish connections to drivers affecting both sides of the terminator; tail activations and substorms on the nightside, large amplitude ULF waves, solar wind sudden impulses, and rapid changes in MIC current systems on the dayside. The short duration of these events, coupled with the use of conjugate satellite measurements and ground magnetometer arrays when possible, allows us to investigate their localization and the latitudinal extent of their effects. Overall we further examine the potential role of non-substorm phenomena in generating the GICs which may have adverse impacts on electrical power grids.
Swarm Observations of ULF Pulsation Activity and the August 2016 Central Italy Earthquake
1National Observatory of Athens, Greece; 2Istituto Nazionale di Geofisica e Vulcanologia, Italy; 3Centre national d'études spatiales, France
There have been several studies suggesting that ultra low frequency (ULF) pulsations may be associated with earthquakes. The majority of these studies refers to the detection of these signals in ground-based magnetometer measurements. On the other hand, there is only a handful of studies that have been attempted to correlate ULF pulsations with seismic activity from space-borne magnetometer measurements using low Earth orbit (LEO) satellites (e.g. CHAMP, DEMETER). A 6.2 magnitude near-surface earthquake hit Central Italy on 24 August 2016 at 01:36 UT causing the death of almost 300 people. The Swarm satellites were flying above the epicenter area only a few hours before the occurrence of the earthquake. Satellite passes above the epicenter areas close to the time of occurrence of big earthquakes are rather rare. Herein, we study the ULF pulsation activity observed by Swarm mission a few days before and after the Central Italy earthquake and compare to ground-based magnetometer recordings.
Ionosphere Precursors before Large Earthquakes
The Institute of Crustal Dynamics, China Earthquake Administration, China
From single satellite observations (e.g., DEMETER satellite), various previous works have proved that ionosphere behaves abnormal before large earthquakes. However, there are also some unsolved problems from single spacecraft observations. For example, it is impossible to describe ionosphere abnormal differences for different altitude around the epicenter area. Fortunately, ESA’s SWARM mission, which includes three satellites A, B and C, will provide a unique chance to solve some of these problems. In this work, ionospheric precursors before several large earthquakes will be introduced, and their phenomena in different altitude will be discussed.
Quasi Simultaneous Tropical Cyclone And Earthquake Action On The Ionosphere
1The “Seeingear”elibrary, Battle, United Kingdom; 2Space Research Institute, Moscow, Russian Federation
Rune Floberghagen, ESA’s Swarm mission manager, said, “We have very few ways of probing deep into the structure of our planet, but Swarm is making extremely valuable contributions to understanding Earth’s interior, which then adds to our knowledge of how Earth works as a whole system.”
The evidence that our planet works as a whole system could be better demonstrated in extreme situations - global cataclysms or hazards. We use different major characteristics to separate these disasters. But often we have situation when disasters are close to each to others. It's no secret that tropical cyclone often accompanies earthquake during tropical season.
Tropical cyclone (TC) is only one of several major natural disasters. There are also earthquakes, floods, fires, volcanic eruptions and many more. It is desirable, where possible, to give advance warning of an impending disaster so that people can take evasive action. An earthquake strikes suddenly and often without specific warning and a lot of scientific research has been devoted to attempting to predict earthquakes. In one sense a TC strikes suddenly; it comes in from the ocean and its damage is (mostly) done where and when it reaches the land. But before it makes landfall it has been tracked for quite a while and it has built up as it has travelled across the ocean, gathering strength as it goes. The problem is on following the TC over a matter of a few days before it makes landfall and predicting exactly where and when it will strike the land.
We do not know the real reason for TC's birth. We cannot predict the life length of a tropical cyclone. We know how to classify TC. We can observe its birth, progress and death. We know the area where hurricanes can appear. For example, it is common for TC's to appear in areas where earthquakes are active. But we don't know why. Do we know all about TC's? Answer is “Of course, not”.
What is a possible mechanism for the interaction of different layers like lithosphere, atmosphere and ionosphere during hurricane action? It has been proved that processes in the lithosphere have an electrodynamic influence on the ionosphere. Two of the possible “Earthquakes – Ionosphere” and “TC-Ionosphere” interaction mechanisms are the Gravity Waves and the electric. The ionosphere is important element in the "Earthquakes - TCs“ interaction. It is extremely difficult to establish the precisely effect that the presiding earthquake has had on the TC by measuring ionospheric parameters.
With new opened SWARM data the author has possibilities to discuss a possible electrodynamic influence on the ionosphere during TC action. In this presentation the author analyzes the dynamic ocean parameters, earthquake and ionospheric parameters, received in the process of satellite remote sensing above TC (above Australia) in the last years in the south-eastern area of the East hemisphere. The aim of this topic to assess the contribution of both possible “Earthquakes – Ionosphere” and “TC-Ionosphere” mechanisms during quasi simultaneous TC and earthquake action on the ionosphere.
Analysis of Local Anomalous Characteristics of Lithospheric Magnetic Field before Pishan M6. 5 Earthquake in Xinjiang in 2015
China Earthquake Administration of Xinjiang, China, People's Republic of
Mobile vector geomagnetic survey is a kind of method to obtain seismic precursor, experimentation and survey proved, the value of geomagnetic anomalies is small which caused by earthquake preparation, so we should as far as possible to elimination errors of data processing. By using the stable performance and high accuracy instruments, we obtained the accurate and reliable three-phases mobile geomagnetic vector observation data in the north and south Tianshan Mountain area during 2013 and 2014. We eliminate the effects of the diurnal variation and the secular variation of the geomagnetic field through correction, calculate each terms surface spline model of the interior geomagnetic field, separate the distribution of the geomagnetic anomalous field, and get the differences between two successive terms of the geomagnetic anomalous field and acquire the variation of the geomagnetic anomalous field. Then we analyzed the dynamic variation characteristics of the lithosphere local magnetic field before Pishan M6.5 on Jul. 3, 2015 in Xinjiang to research its relationship with the earthquake. The analysis result showed that there is a certain corresponding relationship between the local anomaly of the lithospheric magnetic field and the earthquake in the area, all the elements of the lithosphere magnetic field show abnormal characteristics before the earthquake.
Detecting Seismic Anomalies from Satellite and Ground Based Electromagnetic Data Using Big Data Analytics Approaches
1Ulster University, United Kingdom; 2Key Laboratory of Earthquake Dynamics of China, Institute of Geology, China Earthquake
This work will report the comparative studies undertaken in the project supported by the Dragon 3 programme – the largest cooperation between European Space Agency and Ministry of Science and Technology of China – which is aimed to developing viable methods and techniques for detecting anomalies from space and terrestrial electromagnetic data that are observed by the SWARM satellite and the network of the Control Source Extremely Low Frequency (CSELF) in China and investigating the correlation between anomalies and earthquakes. We have developed a number of algorithms for detecting anomalies from time series data and evaluated them over benchmark datasets, as well as preliminarily on Outgoing Longwave Radiation observed by the NOAA satellites and electromagnetic data observed by the Swarm satellites and the network of the Control Source Extremely Low Frequency (CSELF). We first will presents the development of anomaly detection algorithms, including Geometric Moving Average Martingale (GMAM) method, Weighted Local Outlier Factor LOF method and Hot SAX methods, the Cumulative Sum (CUSUM) and the Exponentially Weighted Moving Average (EWMA), and two variants of a combined Cusum-EWMA. Secondly we will describe various comparative analysis methodology. Finally by incorporate the Wenchuan, Lushan, Puer, Haiti earthquakes, we present the various comparative case study analysis results over the Swarm and CSELF data sets.
Statistical Analysis of Magnetic Field Disturbances Before Major Earthquakes Based on the DEMETER Magnetic Waveform Data
Institute of Crustal Dynamics, China Earthquake Administration, China, People's Republic of
The first satellite of the China Seismo-electromagnetic Satellite Mission (CSES) will be launched in August 2017. The scientific data processing system of 8 payloads is on the last test phase. However, many processing technical details can be determined by another better schedule. The DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) mission, especially its data applications, give us a clear guide to process the CSES test data.
Publications based on DEMETER science data, including the spectrum and waveform of electromagnetic (EM) data and plasma data, suggested that the DEMETER scientific data are reliable. However, the studies based on the waveform data of Instrument Magnétomètre Search-Coil (IMSC) are rare. Many information related to earthquakes embedded in these waveform data is cannot be provided by the spectrum. This studies aim at (1) obtaining science data processing experiences and (2) mining deep information of EM anomalies may related to earthquakes.
Processing on the waveform data of magnetic field obtained by DEMETER micro-satellite was conducted. Statistical characteristics of the disturbances before major earthquakes (larger than M7.0) during 2005-2010 were extracted. First, the preprocessing, including removing linear drifts of the instrument and the interferences from the satellite platform, was conducted. Second, the background of the waveform field was constructed, using three months’ data before major earthquakes in the 6 years’ revisiting data. Meanwhile, an index demonstrating the complexity of the magnetic waveform data was defined to identify anomalies. Further, the statistical studies on the differences between the magnetic field during major earthquakes and the background were conducted based on this complexity index.
Occurrence Of Schumann Resonances In Swarm ASM Burst Mode Data
1British Geological Survey, United Kingdom; 2Institute de Physique du Globe de Paris, France
The Schumann Resonances (SR) consist of a series of peaks in spectral power in the magnetic and electric field at frequencies of around 8, 14, 22 and 27 Hz. They arise from the continuous occurrence of equatorial lightning strikes which are on average contained within a single source region at any one time during the day, following the sub-solar point. The broadband electromagnetic emission from each lightning strike is contained within a waveguide, bounded by the Earth’s surface and the ionosphere at around 110 km in altitude. Thus particular EM wavelengths can resonate effectively for a few cycles before dissipating. The strike rate is around 100/second which leads to the formation of a steady background signal. The SR are detectable on the ground using sensitive search-coil magnetometers and have peak power of around 5 pT/√(Hz) in the first resonance, diminishing with increased frequency in the magnetic components. They have a large Q-factor (i.e. broad peaks) and an obvious diurnal and seasonal variation due to the location of the continents.
Although, the electric field from SR have been detected in space using the C/NOFS satellite in 2010/11 at altitudes of 600 km, there have been no confirmed measurements using magnetic field instruments. There are theoretical arguments that the ionosphere acts to fully shield the magnetic signal from penetrating out of the atmosphere to Swarm altitudes, though other models suggest some secondary signals may be excited by the SR. We examine the Swarm ASM Burst Mode data (250 Hz) collected on the 19-Jan-2014 during the commissioning phase of the mission to look for signals which could be attributable to the SR.