Fabian Euchner

Last Name

Euchner

First Name

Fabian

ORCID

0000-0001-6340-7439

Organisational unit

03476 - Giardini, Domenico / Giardini, Domenico

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Publications 1 - 10 of 26

Super high frequency events: a new class of events recorded by the InSight seismometers on Mars
Dahmen, Nikolaj L.; Clinton, John Francis; Ceylan, Savas; et al. (2021)
Journal of Geophysical Research: Planets
We present a new class of seismic signals that are recorded by the seismometer placed on the surface of Mars as part of the NASA InSight mission. The signals, termed super high frequency (SF) events, are of short duration (∼20 s), with high‐frequency energy between ∼5–30 Hz that is dominant on the horizontal components, and are often comparable in amplitude. For detection and characterization of SF events, we employ the available continuous 20 samples per second (sps) data from the Very Broadband instrument. Due to bandwidth limitations, 100 sps data from the short‐period sensor are only partially available, but aid in analysis of the frequency content above 10 Hz and help distinguish the events from high‐frequency noise. From June 2019 to May 2020, 780 SF events have been detected. The events are observed to occur in repeatable patterns that last for weeks. Initially the SF events clustered in the hours before sunset, but, more recently, have spread across the evening period. Based on template matching techniques, we have identified 16 distinct families that generally follow the temporal clusters. A thermal origin of these events is suggested, since the majority of the events fall within a ±2 hour time window around sunset with extreme temperature changes. The SF events have similarities with thermal events observed on the lunar surface from data collected during the Apollo missions.
First focal mechanisms of marsquakes
Brinkman, Nienke; Stähler, Simon Christian; Giardini, Domenico; et al. (2021)
Journal of Geophysical Research: Planets
Since February 2019, NASA’s InSight lander is recording seismic signals on the planet Mars, which, for the first time, allows to observe ongoing tectonic processes with geophysical methods. A number of Marsquakes have been located in the Cerberus Fossae graben system in Elysium Planitia and further west, in the Orcus Patera depression. We present a first study of the focal mechanisms of three well‐recorded events (S0173a, S0183a, S0235b) to determine the processes dominating in the source region. We infer for all three events a predominantly extensional setting. Our method is adapted to the case of a single, multi‐component receiver and based on fitting waveforms of P and S waves against synthetic seismograms computed for the initial crustal velocity model derived by the InSight team. We explore the uncertainty due to the single station limitation and find that even data recorded by one station constrains the mechanisms (reasonably) well. For the events in the Cerberus Fossae region (S0173a, S0235b) normal faulting with a relatively steep dipping fault plane is inferred, suggesting an extensional regime mainly oriented E‐W to NE‐SW. The fault regime in the Orcus Patera region is not determined uniquely because only the P wave can be used for the source inversion. However, we find that the P and weak S waves of the S0183a event show similar polarities to the event S0173, which indicates similar fault regimes.
High‐Frequency Seismic Events on Mars Observed by InSight
van Driel, Martin; Ceylan, Savas; Clinton, John Francis; et al. (2021)
Journal of Geophysical Research: Planets
The seismometer deployed on the surface of Mars as part of the InSight mission (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) has recorded several hundreds of marsquakes in the first 478 sols after landing. The majority of these are classified as high‐frequency (HF) events in the frequency range from approximately 1 to 10 Hz on Mars' surface. All the HF events excite a resonance around 2.4 Hz and show two distinct but broad arrivals of seismic energy that are separated by up to 450 s. Based on the frequency content and vertical‐to‐horizontal energy ratio, the HF event family has been subdivided into three event types, two of which we show to be identical and only appear separated due to the signal‐to‐noise ratio. We show here that the envelope shape of the HF events is explained by guided Pg and Sg phases in the Martian crust using simple layered models with scattering. Furthermore, the relative travel times between these two arrivals can be related to the epicentral distance, which shows distinct clustering. The rate at which HF events are observed varies by an order of magnitude over the course of one year and cannot be explained by changes of the background noise only. The HF content and the absence of additional seismic phases constrain crustal attenuation and layering, and the coda shape constrains the diffusivity in the uppermost shallow layers of Mars. © 2021 American Geophysical Union
Preparing for InSight: Evaluation of the Blind Test for Martian Seismicity
van Driel, Martin; Ceylan, Savas; Clinton, John Francis; et al. (2019)
Seismological Research Letters
Largest recent impact craters on Mars: Orbital imaging and surface seismic co-investigation
Posiolova, Liliya V.; Lognonné, Philippe Henri; Banerdt, William Bruce; et al. (2022)
Science
Two >130-meter-diameter impact craters formed on Mars during the later half of 2021. These are the two largest fresh impact craters discovered by the Mars Reconnaissance Orbiter since operations started 16 years ago. The impacts created two of the largest seismic events (magnitudes greater than 4) recorded by InSight during its 3-year mission. The combination of orbital imagery and seismic ground motion enables the investigation of subsurface and atmospheric energy partitioning of the impact process on a planet with a thin atmosphere and the first direct test of martian deep-interior seismic models with known event distances. The impact at 35°N excavated blocks of water ice, which is the lowest latitude at which ice has been directly observed on Mars.
S1222a – The Largest Marsquake Detected by InSight
Kawamura, Taichi; Clinton, John Francis; Zenhäusern, Géraldine; et al. (2023)
Geophysical Research Letters
NASA’s InSight has detected a large magnitude seismic event, labelled S1222a. The event has a moment magnitude of M(Ma)(W)4.7, with 5 times more seismic moment compared to the second largest even. The event is so large that features are clearly observed that were not seen in any previously detected events. In addition to body phases and Rayleigh waves, we also see Love waves, minor arc surface wave overtones, and multi-orbit surface waves. At long periods, the coda event exceeds 10 hours. The event locates close to the North-South dichotomy and outside the tectonically active Cerberus Fossae region. S1222a does not show any evident geological or tectonic features. The event is extremely rich in frequency content, extending from below 1/30 Hz up to 35 Hz. The event was classified as a broadband type event; we also observe coda decay and polarization similar to that of very high frequency type events.
SEIS: Insight’s Seismic Experiment for Internal Structure of Mars
Lognonne, Philippe; Giardini, Domenico; Zweifel, Peter; et al. (2019)
Space Science Reviews
By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∼2500 at 1 Hz and ∼200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of Mw∼3 at 40∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.
The Marsquake catalogue from InSight, sols 0–478
Clinton, John Francis; Ceylan, Savas; van Driel, Martin; et al. (2021)
Physics of the Earth and Planetary Interiors
The InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission began collecting high quality seismic data on Mars in February 2019. This manuscript documents the seismicity observed by SEIS, InSightâ€™s seismometer, from this time until the end of March 2020. Within the InSight project, the Marsquake Service (MQS) is responsible for prompt review of all seismic data collected by InSight, detection of events that are likely to be of seismic origin, and curation and release of seismic catalogues. In the first year of data collection, MQS have identified 465 seismic events that we interpret to be from regional and teleseismic marsquakes. Seismic events are grouped into 2 different event families: the low frequency family is dominated by energy at long period below 1 s, and the high frequency family primarily include energy at and above 2.4 Hz. Event magnitudes, from Mars-specific scales, range from 1.3 to 3.7. A third class of events with very short duration but high frequency bursts have been observed 712 times. These are likely associated with a local source driven by thermal stresses. This paper describes the data collected so far in the mission and the procedures under which MQS operates; summarises the content of the current MQS seismic catalogue; and presents the key features of the events we have observed so far, using the largest events as examples.
Seismic High-Resolution Acquisition Electronics for the NASA InSight Mission on Mars
Zweifel, Peter; Mance, Davor; ten Pierick, Jan; et al. (2021)
Bulletin of the Seismological Society of America
The Seismic Experiment for Interior Structures (SEIS) was deployed on Mars in November 2018 and began science operations in March 2019. SEIS is the primary instrument of the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission, which was launched by the National Aeronautics and Space Administration (NASA). The acquisition and control (AC) electronics is a key element of SEIS. The AC acquires the seismic signals of the two sets of seismic sensors with high resolution, stores the data in its local nonvolatile memory for later transmission by the lander, and controls the numerous functions of SEIS. In this article, we present an overview of the AC with its connections to the sensors and to the lander, as well as its functionality. We describe the elements of the acquisition chains and filters, and discuss the performance of the seismic and temperature channels. Furthermore, we outline the safety functions and health monitoring, which are of paramount importance for reliable operation on Mars. In addition, we analyze an artefact affecting the seismic data referred to as the "tick-noise" and provide a method to remove this artefact by post-processing the data.
Magnitude Scales for Marsquakes Calibrated from InSight Data
Böse, Maren; Stähler, Simon Christian; Deichmann, Nicholas; et al. (2021)
Bulletin of the Seismological Society of America

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