scholarly journals Analysis of Ocean Bottom Pressure Anomalies and Seismic Activities in MedRidge Zone

2021 ◽  
Author(s):  
Senol Hakan Kutoglu ◽  
Kazimierz Becek
Keyword(s):  
Time Series ◽  
Subduction Zones ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Vertical Movements ◽  
Ocean Bottom Pressure ◽  
Continuous Mass ◽  
Mediterranean Ridge Accretionary Complex ◽  
Gravity Recovery ◽  
Periodic Components

Mediterranean Ridge accretionary complex (MAC) is one of the most critical subduction zones in the world. It is known that the region exhibits a continuous mass change (horizontal/vertical movements). This process is associated with the devastating and tragic earthquakes shaking the MAC for centuries. Here, we investigate the ocean bottom pressure (OBP) anomalies in the MAC derived from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow On (GRACE-FO) satellite missions. The OBP time series for the MAC comprises a decreasing trend in addition to 1-, 1.53-, 2.36-, 3.67-, and 9.17-year periodic components partially explained by the atmosphere, oceans, and hydrosphere (AOH) processes, and Earth's pole movement. We noticed that the OBP anomalies appear to link to a rising trend and periods in earthquakes' power time series. This finding sheds new light on the mechanisms controlling the most destructive natural hazard.

scholarly journals Analysis of Ocean Bottom Pressure Anomalies and Seismic Activities in the MedRidge Zone

2021 ◽  
Vol 13 (7) ◽  
pp. 1242
Author(s):  
Hakan S. Kutoglu ◽  
Kazimierz Becek
Keyword(s):  
Time Series ◽  
Mass Change ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Vertical Movements ◽  
Ocean Bottom Pressure ◽  
Continuous Mass ◽  
Mediterranean Ridge Accretionary Complex ◽  
Gravity Recovery ◽  
Periodic Components

The Mediterranean Ridge accretionary complex (MAC) is a product of the convergence of Africa–Europe–Aegean plates. As a result, the region exhibits a continuous mass change (horizontal/vertical movements) that generates earthquakes. Over the last 50 years, approximately 430 earthquakes with M ≥ 5, including 36 M ≥ 6 earthquakes, have been recorded in the region. This study aims to link the ocean bottom deformations manifested through ocean bottom pressure variations with the earthquakes’ time series. To this end, we investigated the time series of the ocean bottom pressure (OBP) anomalies derived from the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) satellite missions. The OBP time series comprises a decreasing trend in addition to 1.02, 1.52, 4.27, and 10.66-year periodic components, which can be explained by atmosphere, oceans, and hydrosphere (AOH) processes, the Earth’s pole movement, solar activity, and core–mantle coupling. It can be inferred from the results that the OBP anomalies time series/mass change is linked to a rising trend and periods in the earthquakes’ energy time series. Based on this preliminary work, ocean-bottom pressure variation appears to be a promising lead for further research.

scholarly journals The Observed North Atlantic Meridional Overturning Circulation: Its Meridional Coherence and Ocean Bottom Pressure

2014 ◽  
Vol 44 (2) ◽  
pp. 517-537 ◽  
Author(s):  
Shane Elipot ◽  
Eleanor Frajka-Williams ◽  
Chris W. Hughes ◽  
Josh K. Willis
Keyword(s):  
Time Series ◽  
North Atlantic ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Western Boundary ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Overturning Circulation ◽  
Ocean Bottom Pressure ◽  
Meridional Overturning

Abstract Analyses of meridional transport time series from the Rapid Climate Change–Meridional Overturning Circulation (RAPID MOC) array at 26°N and from Argo float and altimetry data at 41°N reveal that, at semiannual and longer time scales, the contribution from the western boundary dominates the variability of the North Atlantic meridional overturning circulation (MOC), defined as the transport in the upper 1000 m of the ocean. Because the variability of the western boundary contribution is associated with a geostrophic overturning, it is reflected in independent estimates of transports from gradient of ocean bottom pressure (OBP) relative to and below 1000 m on the continental slope of the western boundary at three nominal latitudes (26°, 39°, and 42.5°N). Time series of western meridional transports relative to and below 1000 m derived from the OBP gradient, or equivalently derived from the transport shear profile, exhibit approximately the same phase relationship between 26° and 39°–42.5°N as the western contribution to the geostrophic MOC time series do: the western geostrophic MOC at 41°N precedes the MOC at 26°N by approximately a quarter of an annual cycle, resulting in a zero correlation at this time scale. This study therefore demonstrates how OBP gradients on basin boundaries can be used to monitor the MOC and its meridional coherence.

scholarly journals Monitoring Atlantic overturning circulation and transport variability with GRACE-type ocean bottom pressure observations – a sensitivity study

Ocean Science ◽  
2015 ◽  
Vol 11 (6) ◽  
pp. 953-963 ◽  
Author(s):  
K. Bentel ◽  
F. W. Landerer ◽  
C. Boening
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Sensitivity Study ◽  
Ocean Basin ◽  
Meridional Overturning Circulation ◽  
Western Slope ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Overturning Circulation ◽  
Ocean Bottom Pressure

Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism for large-scale northward heat transport and thus plays an important role for global climate. Relatively warm water is transported northward in the upper layers of the North Atlantic Ocean and, after cooling at subpolar latitudes, sinks down and is transported back south in the deeper limb of the AMOC. The utility of in situ ocean bottom pressure (OBP) observations to infer AMOC changes at single latitudes has been characterized in the recent literature using output from ocean models. We extend the analysis and examine the utility of space-based observations of time-variable gravity and the inversion for ocean bottom pressure to monitor AMOC changes and variability between 20 and 60° N. Consistent with previous results, we find a strong correlation between the AMOC signal and OBP variations, mainly along the western slope of the Atlantic Basin. We then use synthetic OBP data – smoothed and filtered to resemble the resolution of the GRACE (Gravity Recovery and Climate Experiment) gravity mission, but without errors – and reconstruct geostrophic AMOC transport. Due to the coarse resolution of GRACE-like OBP fields, we find that leakage of signal across the step slopes of the ocean basin is a significant challenge at certain latitudes. Transport signal rms is of a similar order of magnitude as error rms for the reconstructed time series. However, the interannual AMOC anomaly time series can be recovered from 20 years of monthly GRACE-like OBP fields with errors less than 1 sverdrup in many locations.

scholarly journals Validation of the EGSIEM GRACE Gravity Fields Using GNSS Coordinate Timeseries and In-Situ Ocean Bottom Pressure Records

2018 ◽  
Vol 10 (12) ◽  
pp. 1976 ◽  
Author(s):  
Qiang Chen ◽  
Lea Poropat ◽  
Liangjing Zhang ◽  
Henryk Dobslaw ◽  
Matthias Weigelt ◽  
...  
Keyword(s):  
Time Series ◽  
Signal To Noise Ratio ◽  
Satellite System ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Ocean Bottom Pressure ◽  
Global Gravity ◽  
Gravity Fields ◽  
Global Navigation Satellite

Over the 15 years of the Gravity Recovery and Climate Experiment (GRACE) mission, various data processing approaches were developed to derive time-series of global gravity fields based on sensor observations acquired from the two spacecrafts. In this paper, we compare GRACE-based mass anomalies provided by various processing groups against Global Navigation Satellite System (GNSS) station coordinate time-series and in-situ observations of ocean bottom pressure. In addition to the conventional GRACE-based global geopotential models from the main processing centers, we focus particularly on combined gravity field solutions generated within the Horizon2020 project European Gravity Service for Improved Emergency Management (EGSIEM). Although two validation techniques are fully independent from each other, it is demonstrated that they confirm each other to a large extent. Through the validation, we show that the EGSIEM combined long-term monthly solutions are comparable to CSR RL05 and ITSG2016, and better than the other three considered GRACE monthly solutions AIUB RL02, GFZ RL05a, and JPL RL05.1. Depending on the GNSS products, up to 25.6% mean Weighted Root-Mean-Square (WRMS) reduction is obtained when comparing GRACE to the ITRF2014 residuals over 236 GNSS stations. In addition, we also observe remarkable agreement at the annual period between GNSS and GRACE with up to 73% median WRMS reduction when comparing GRACE to the 312 EGSIEM-reprocessed GNSS time series. While the correspondence between GRACE and ocean bottom pressure data is overall much smaller due to lower signal to noise ratio over the oceans than over the continents, up to 50% agreement is found between them in some regions. The results fully confirm the conclusions found using GNSS.

Arctic Ocean bottom pressure variations from 2002 to 2020: merging GRACE with GRACE-FO

2020 ◽  
Author(s):  
Cecilia Peralta-Ferriz ◽  
James Morison ◽  
Jennifer Bonin
Keyword(s):  
Time Series ◽  
Arctic Ocean ◽  
Ocean Circulation ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Ocean Bottom Pressure ◽  
The North ◽  
Circulation Patterns ◽  
Arctic Ocean Circulation

<p>Ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) revealed Arctic Ocean circulation patterns and variability that were previously unknown (Morison et al., 2007; Morison et al., 2012; Peralta-Ferriz et al., 2014). OBP measurements from the GRACE Follow-On mission (GRACE-FO) are therefore increasingly important for monitoring Arctic Ocean variability, and critical for understanding and predicting the fate of the rapidly changing Arctic environment.</p> <p>In this work we use GRACE data from 2002 to 2017 jointly with a 10-year record of <em>in situ</em> OBP at the North Pole (2005-2015) complemented with <em>in situ</em> OBP in the Canada Basin (2015-2018), and wind reanalysis products, to create a proxy representation of the OBP anomalies that explains the largest possible fraction of the observed OBP variability in the Arctic Ocean and the Nordic Seas. We do this by performing a linear regression analysis, combined with maximum covariance analysis (MCA) – a technique that was tested prior to the decommission of GRACE and the launch of GRACE-FO (Peralta-Ferriz et al., 2016). Here, the first predictor time series is the <em>in situ</em> OBP record at the North Pole and Canada Basin; the second predictor time series is the expansion coefficients time series of the leading mode of MCA between the GRACE OBP coupled with the winds. We use this proxy OBP to merge GRACE with the first 2 years of available GRACE-FO OBP. We compare our merged OBP field with OBP output from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS). Preliminary results suggest a good agreement between the proxy and predicted OBP fields and both GRACE and GRACE-FO data, especially in the central Arctic, but also in the Nordic Seas. The OBP variations from the merged GRACE and GRACE-FO and from PIOMAS will be also explored.</p> <p><strong>References:</strong></p> <ul> <li>Morison, J. H., J. Wahr, R. Kwok and C. Peralta-Ferriz (2007), Recent trends in Arctic Ocean mass distribution revealed by GRACE, Res. Lett.,34, L07602, doi:10.1029/2006GL029016.</li> <li>Morison, J., R. Kwok, C. Peralta-Ferriz, M. Alkire, I. Rigor, R. Andersen and M. Steele (2012), Changing Arctic Ocean freshwater pathways. Nature, 481, 66-7</li> <li>Peralta-Ferriz, C., J. H. Morison, J. M. Wallace, J. Bonin and J. Zhang (2014), Arctic Ocean circulation patterns revealed by GRACE, of Climate, 27:1445–1468 doi:10.1175/JCLI-D-13-00013.1.</li> <li>Peralta-Ferriz, C., J. H. Morison and J. M. Wallace(2016), Proxy representation of Arctic ocean bottom pressure variability: Bridging gaps in GRACE observations,  Res. Lett., 43, 9183–9191, doi:10.1002/2016GL070137</li> </ul>

Near-field tsunami forecasting from cabled ocean bottom pressure data

2009 ◽  
Vol 114 (B6) ◽  
Author(s):  
Hiroaki Tsushima ◽  
Ryota Hino ◽  
Hiromi Fujimoto ◽  
Yuichiro Tanioka ◽  
Fumihiko Imamura
Keyword(s):  
Near Field ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Pressure Data ◽  
Ocean Bottom Pressure ◽  
Tsunami Forecasting

scholarly journals Seafloor Crustal Deformation on Ocean Bottom Pressure Records With Nontidal Variability Corrections: Application to Hikurangi Margin, New Zealand

2019 ◽  
Vol 46 (1) ◽  
pp. 303-310 ◽  
Author(s):  
Tomoya Muramoto ◽  
Yoshihiro Ito ◽  
Daisuke Inazu ◽  
Laura M. Wallace ◽  
Ryota Hino ◽  
...  
Keyword(s):  
New Zealand ◽  
Crustal Deformation ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
Ocean Bottom Pressure
Sign in / Sign up

Export Citation Format

Share Document