Possible Mechanisms for Generation of Anomalously High PGA During the 2011 Tohoku Earthquake

Possible Mechanisms for Generation of Anomalously High PGA During the 2011 Tohoku Earthquake Mechanisms are suggested that could explain anomalously high PGAs (peak ground accelerations) exceeding 1 g recorded during the 2011 Tohoku earthquake (M w = 9.0). In my previous research, I studied soil behavior during the Tohoku earthquake based on KiK-net vertical array records and revealed its ‘atypical’ pattern: instead of being reduced in the near-source zones as usually observed during strong earthquakes, shear moduli in soil layers increased, indicating soil hardening, and reached their maxima at the moments of the highest intensity of strong motion, then reduced. We could explain this assuming that the soils experienced some additional compression. The observed changes in the shapes of acceleration time histories with distance from the source, such as a decrease of the duration and an increase of the intensity of strong motion, indicate phenomena similar to overlapping of seismic waves and a shock wave generation, which led to the compression of soils. The phenomena reach their maximum in the vicinity of stations FKSH10, TCGH16, and IBRH11, where the highest PGAs were recorded; at larger epicentral distances, PGAs sharply fall. Thus, the occurrence of anomalously high PGAs on the surface can result from the combination of the overlapping of seismic waves at the bottoms of soil layers and their increased amplification by the pre-compressed soils. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Pure and Applied Geophysics Springer Journals

Possible Mechanisms for Generation of Anomalously High PGA During the 2011 Tohoku Earthquake

Loading next page...
 
/lp/springer_journal/possible-mechanisms-for-generation-of-anomalously-high-pga-during-the-k0zCik4B0i
Publisher
Springer Journals
Copyright
Copyright © 2017 by Springer International Publishing
Subject
Earth Sciences; Geophysics/Geodesy
ISSN
0033-4553
eISSN
1420-9136
D.O.I.
10.1007/s00024-017-1558-2
Publisher site
See Article on Publisher Site

Abstract

Mechanisms are suggested that could explain anomalously high PGAs (peak ground accelerations) exceeding 1 g recorded during the 2011 Tohoku earthquake (M w = 9.0). In my previous research, I studied soil behavior during the Tohoku earthquake based on KiK-net vertical array records and revealed its ‘atypical’ pattern: instead of being reduced in the near-source zones as usually observed during strong earthquakes, shear moduli in soil layers increased, indicating soil hardening, and reached their maxima at the moments of the highest intensity of strong motion, then reduced. We could explain this assuming that the soils experienced some additional compression. The observed changes in the shapes of acceleration time histories with distance from the source, such as a decrease of the duration and an increase of the intensity of strong motion, indicate phenomena similar to overlapping of seismic waves and a shock wave generation, which led to the compression of soils. The phenomena reach their maximum in the vicinity of stations FKSH10, TCGH16, and IBRH11, where the highest PGAs were recorded; at larger epicentral distances, PGAs sharply fall. Thus, the occurrence of anomalously high PGAs on the surface can result from the combination of the overlapping of seismic waves at the bottoms of soil layers and their increased amplification by the pre-compressed soils.

Journal

Pure and Applied GeophysicsSpringer Journals

Published: Apr 28, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off