Matthias Hort

Universität Hamburg

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

B. Langmann

Universität Hamburg

Klemen Zakšek

Universität Hamburg

L. Scharff

Universität Hamburg

R. Seyfried

Ingenieurgesellschaft Auto und Verkehr (Germany)

Jason Phipps Morgan

Southern University of Science and Technology

Malte Vöge

Norwegian Geotechnical Institute

Lars Rüpke

GEOMAR Helmholtz Centre for Ocean Research Kiel

Gholam Ali Hoshyaripour

Karlsruhe Institute of Technology

Tilman Spohn

Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

A. Gerst

European Space Research and Technology Centre

Cooperative Institutions

Universität Hamburg

Centre National de la Recherche Scientifique

Laboratoire Magmas et Volcans

Institut de Recherche pour le Développement

Istituto Nazionale di Geofisica e Vulcanologia

Université Clermont Auvergne

Ludwig-Maximilians-Universität München

Kiel University

GEOMAR Technologie GmbH - GTG

Max Planck Society

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Meteorological influence on the seasonal and diurnal variability of the dispersion of volcanic emissions in Nicaraguan: a numerical model study

B. Langmann Matthias Hort Thor H. Hansteen

Diurnal temperature variation

Source

Cite

Citations (0)

Pulsed Vulcanian explosions: A characterization of eruption dynamics using Doppler radar

Geology (2015)

L. Scharff Matthias Hort Nick Varley

Understanding the dynamics of ongoing volcanic eruptions is essential for predicting the input and transport of volcanic ash in the atmosphere. To constrain near-vent dynamic processes of explosive Vulcanian events, we used Doppler radar measurements, providing tephra velocities and a proxy of the mass flux, in two field experiments at Volcan de Colima (Mexico) and Santiaguito (Guatemala). We find that explosive eruptions at both volcanoes consist of individual degassing pulses. The analysis of the timing of such pulses shows that both volcanoes have preferred interpulse times of 3 s (Santiaguito) and 2–5 s (Volcan de Colima). The interpulse time during one event may change, but it often returns to the preferred interpulse time. This behavior is similar at both volcanoes and the interpulse time roughly follows a log-logistic distribution indicating the interplay of two competing processes. These could be short-duration degassing of the uppermost conduit versus decreasing permeability due to progressive gas loss and compaction during an eruption.

Vulcanian eruption

10.1130/g36705.1

Cite

Citations (16)

Using picosatellites for 4-D imaging of volcanic clouds: Proof of concept using ISS photography of the 2009 Sarychev Peak eruption

Remote Sensing of Environment (2018)

Klemen Zakšek M. R. James Matthias Hort Tiago Nogueira Klaus Schilling

Volcanic ash

Cloud top

Structure from Motion

10.1016/j.rse.2018.02.061

Cite

Citations (14)

4D velocity of Strombolian eruptions and man-made explosions derived from multiple Doppler radar instruments

Journal of Volcanology and Geothermal Research (2008)

A. Gerst Matthias Hort Philip R. Kyle Malte Vöge

Strombolian eruption

Directivity

10.1016/j.jvolgeores.2008.05.022

Cite

Citations (44)

Continuous monitoring of volcanic eruption dynamics: a review of various techniques and new results from a frequency-modulated radar Doppler system

Bulletin of Volcanology (1999)

R. Seyfried Matthias Hort

Volcanology

Vulcanian eruption

Effusive eruption

Phreatic eruption

Dense-rock equivalent

10.1007/s004450050256

Cite

Citations (31)

Widespread fluid expulsion along the seafloor of the Costa Rica convergent margin

Terra Nova (2002)

Gerhard Bohrmann K. Heeschen Carmen Jung Willi Weinrebe Boris Baranov

Active fluid and gas transport were measured and observed along more than 200 km of the convergent margin of Costa Rica during cruise SO144‐2 aboard RV Sonne . Ten profiles were run with the TV‐sled OFOS, eight of which detected the dense occurrence of cold vent sites. This discovery shows that seafloor fluid expulsion is widely spread along the Pacific margin of Costa Rica. Surficial evidence of fluid expulsion is indicated by the appearance of chemosynthetic vent organisms such as bacterial mats, vesicomyid, solemyid and mytilid bivalves and tubeworms. Numerous active vents were indicated by elevated methane concentrations (≤ 200 nmol L – ) in the bottom water. Although fluid‐venting activity was known previously from a small area south of Nicoya Peninsula, the present study documents active seepage at landslides, headwall scarps related to seamount subduction, morphological intersections of faults and mid‐slope mud volcanoes.

Seamount

Seafloor Spreading

Cold seep

Mud volcano

Chemosynthesis

North American Plate

10.1046/j.1365-3121.2002.00400.x

Cite

Citations (100)

First in-situ observation of a moving natural pyroclastic density current using Doppler radar

Scientific Reports (2019)

L. Scharff Matthias Hort Nick Varley

Abstract Pyroclastic density currents are one of the most devastating volcanic hazards. Understanding their dynamics is a key to develop successful hazard mitigation strategies. The hazard associated with pyroclastic density currents is commonly investigated a posteriori from their deposits or a priori using analogue and numerical experiments. Despite the low probability of observing a natural moving pyroclastic density current, we present the first in-situ analysis of the internal particle velocities of pyroclastic density currents at Volcán de Colima using a Doppler radar. Our data show two Vulcanian explosions, immediately followed by column collapse and a first pyroclastic density current travelling down the south flank with an average speed of 30 m/s (>50 m/s maximum speed) to a distance of 3 km from the crater rim. The direction of the pyroclastic density current coincided with that of the radar beam enabling measurement of velocity spectra (histogram of particle velocities within the radar beam). The measurement geometry enables the simultaneous measurement of the dense undercurrent at the crater rim (with <20 m/s and an increasing echo power over 20 s) and the dilute cloud higher above the topography approaching the radar (with >20 m/s and approximately constant echo power). The presented data set may be used as a benchmark for future experimental and numerical models that simulate the dynamics of pyroclastic density currents. Using the measured velocities of the collapsing column as input for numerical models will permit the validation of the models for the prediction of the true run-out distance, and thus provide valuable information for hazard assessments.

Pyroclastic fall

10.1038/s41598-019-43620-w

Cite

Citations (17)

Constraining the uncertainties of volcano thermal anomaly monitoring using a Kalman filter technique

Geological Society London Special Publications (2013)

Klemen Zakšek Manoochehr Shirzaei Matthias Hort

Abstract The activity status of a volcano can be evaluated from the remotely measured radiant power ( RP ). The measured RP contains noise due to reasons such as atmospheric effects and instrument characteristics. Here we first show how to estimate the uncertainty of each single RP measurement. To additionally reduce the temporal noise of the RP time series we apply a Kalman filter. The Kalman filter is able to recursively analyse an unevenly sampled time series. To validate our filtering scheme, we applied it to an eruption of Etna in 2002, as well as to the eruption of Nyamuragira in 2010. In the case of the Etna eruption, the denoised time series agrees well with in situ observations of a waxing and waning flow. For the case of Nyamuragira, the enhanced time series of RP shows more fluctuation probably due to cloud coverage. Thus, we propose a multiple instrument approach that increases the temporal resolution of the RP time series and reduces the associated noise.

Anomaly (physics)

10.1144/sp380.5

Cite

Citations (13)

Radar Doppler velocimetry of volcanic eruptions: theoretical considerations and quantitative documentation of changes in eruptive behaviour at Stromboli volcano, Italy

Geophysical Journal International (2003)

Matthias Hort R. Seyfried Malte Vöge

The use of radar Doppler velocimetry for the observation of volcanic activity is new. We used this method to continuously observe the activity of one vent of Stromboli volcano, Italy, from the end of 2000 April until early May. During this period we recorded 702 eruptions, 132 of which occurred before a strong rain storm passed over the island on April 29. In order to interpret the recorded Doppler data we developed a program that simulates different strombolian eruption scenarios, for which we then calculate the theoretical Doppler spectra. Comparing our theoretical data with the observed data we are able to show that most of the eruptions are nearly vertical, although we did observe only one component of the eruption vector with our Doppler radar. One of the most interesting features of the data set is a significant change in eruptive behaviour that correlates with the occurrence of the rain storm: we find that on average the eruption duration increased by a factor of 2, eruptive velocities were much higher and indirect evidence indicates that the average particle diameter of the erupted material decreased. This change may have several causes, but the coincidence with the rain storm may be evidence of magma–water interaction and feedback on the volcanic activity. If the fluid source (rain) changing the eruptive style is at the surface and in near-surface layers then the main control on final eruption dynamics at Stromboli volcano must also be in rather shallow regions.

Strombolian eruption

Effusive eruption

Peléan eruption

10.1046/j.1365-246x.2003.01982.x

Cite

Citations (58)

HOBIT-The new Hamburg Ocean Bottom Tiltmeter: A First Deployment at Columbo Seamount, Aegean Sea

AGUFM (2007)

Matthias Hort Martin Hensch Stephan Winter Torsten Dahm

Seamount

Tiltmeter

Ocean bottom

Source

Cite

Citations (0)