Seminar Schedule < Institute For Research on Earth Evolution

2010

● IFREE YES seminar
Time: 14:00-15:30 on 24th December(Friday)
Place: 506 Meeting room, IT building, Yokohama Institute for Earth Sciences
Speaker: Dr. Mizuo Kajino （Meteorological Research Institute）

Title: Sorry, no English title
Abstract: Sorry, no English abstract.

● IFREE YES seminar
Time: 13:00-14:00 on 10 December (Friday)
Place: 5F Meeting room, IT building, Yokohama Institute for Earth Sciences
Speaker: Kyoko Tanaka (Institute of Low Temprature Science Hokkaido University)

Title: Molecular dynamics simulations of homogeneous nucleation from vapor to solid phase

Abstract: Sorry, no English abstract

● IFREE YES seminar
Time: 13:00-14:00 on 29 November (Monday)
Place: 5F Meeting room, IT building, Yokohama Institute for Earth Sciences
Speaker: Sosuke Ohno (Planetary Exploration Research Center, Chiba Institute of Technology)

Title: Experimental study of impact devolatilization of sulfate: implication to the K-Pg mass extinction

Abstract: Sorry, no English abstract

● IFREE YES seminar
Time: 15:00-15:50 on 19 November
Place: Seminar room, annex 1F, YOKOSUKA HQ
Speaker: Dr. Osamu Ishizuka (AIST)

Title: Geological outline of Izu-Bonin forearc and IBM2 drilling proposal

● IFREE YES seminar
Time: 16:00-17:30 on 19 Oct. (Tuesday)
Place: 403&404 Meeting room, IT building, Yokohama Institute for Earth Sciences
Speaker: Prof. Yehuda Ben-Zion (Department of Earth Sciences, University of Southern California)

Title：Rock damage, Earthquakes and Faults (in the Brittle Crust)

Abstract：
We review observational and theoretical results on seismic radiation
and brittle rock damage in two complementary problems. (i) Rapid
damage generation by sources with sufficiently high amplitude and
subsequent gradual healing. (ii) Effects of brittle rock damage within
the source volume on the seismic radiation to the bulk.
(i) Analysis of seismic data recorded near the North Anatolian fault
shows clear regional reduction of seismic velocities in the top
100-500 meters during the time of the 1999 Mw7.1 Duzce earthquake [1].
Spectral ratios of seismograms recorded at fault-zone and off-fault
sites show changes of spectral curves right after the Duzce earthquake
consistent with a reduction of the S-wave velocity at the fault-zone
site of 20-50% [2]. The co-seismic changes are followed by logarithmic
recovery that is very pronounced in the first day and continues with
appreciable amplitude in the subsequent 3 months. Similar results are
found around other rupture zones [3]. The observations are compatible
with laboratory experiments with granular materials and rocks [4], and
they can be simulated with a nonlinear continuum damage rheology [5].
Since the damage generation is resisted by normal stress, and healing
is enhanced by it, the evolution of rock damage over many earthquake
cycles produces a flower-type fault zone structure, with significant
shallow damage that decreases in amplitude and width with depth [6].
This is consistent with detailed analysis of fault zone trapped waves
and other characteristics of rock damage [7].
(ii) A seismic representation theorem that includes, in addition to
the standard moment term, a damage-related term (stemming from co-
seismic changes of elastic moduli) indicates that the damage-related
radiation is associated with products of the changes of elastic moduli
and the total elastic strain components in the source region [8].
Decreasing elastic moduli in the source region (as produced generally
by brittle deformation of low-porosity rocks and explosions) increase
the radiation to the bulk, while increasing moduli (which may be
produced during the formation of compaction bands in porous rocks)
decrease the radiation. Order of magnitude estimates suggest that the
damage-related contribution to the seismic radiation, which is
neglected in standard calculations, can have appreciable amplitude
that may in some cases be comparable to or larger than the moment
contribution. A decomposition analysis shows that the damage-related
source term has an isotropic component that can be larger than its
double couple component.

References
[1] Peng, Z. & Y. Ben-Zion, Pure Appl. Geophys., 163, 567-600, 2006.
[2] Karabulut, H. & Bouchon, M., Geophys. J. Int., 170, 262-274, 2007.
Wu, C. Z. Peng & Y. Ben-Zion, Geophys. J. Int., 176, 265-278, 2009.
[3] Rubinstein, J. & Beroza, G., Geophys. Res. Lett, 31, L23614, 2004.
Sawazaki, K., Sato, H. H., Nakahara, H. & Nishimura, T., Bull. Seism.
Soc. Am., 99, 352-366, 2009.
[4] Dieterich, J.H. & Kilgore, B.D., Tectonophysics, 256, 219-239,
1996. Johnson, P.A. & Jia, X., Nature, 473, 871-874, 2005.
[5] Lyakhovsky, V., Y. Hamiel, J.-P., Ampuero & Y. Ben-Zion, Geophys.
J. Int., 2009.
[6] Finzi, Y., E. H. Hearn, Y. Ben-Zion & V. Lyakhovsky, Pure Appl.
Geophys., 166, 1537-1573, 2009. Lyakhovsky, V. & Y. Ben-Zion,
Geochem. Geophys. Geosyst., 10, Q11011, 2009. Ma, S. & D. J. Andrews,
J. Geophys. Res., 2010.
[7] Ben-Zion, Y., Z. Peng, D. Okaya, L. Seeber, J. G. Armbruster, N.
Ozer, A. J. Michael, S. Baris & M. Akta, Geophys. J. Int., 152,
699-717, 2003. Peng, Z. and Y. Ben-Zion, Geophys. J. Int., 159,
253-274, 2004. Lewis, M. A. and Y. Ben-Zion, GJI, 2010.
[8] Ben-Zion, Y. and J.-P. Ampuero, Geophys. J. Int., 178, 1351-1356, 2

● IFREE YES seminar
Time: 13:30-15:00 on Aug 19th (Thu)
Place: IT building 5F meeting room (506), YOKOHAMA Institute (YES)
Speaker: Sylwester Arabas (University of Warsaw, Faculty of Physics)

Title: Cloud droplet activation from the perspectives of a novel adaptive moving-sectional air parcel model and the EUCAARI-IMPACT observations

Abstract:
Cloud droplet activation is the very process linking atmospheric thermo-
and hydrodynamics with aerosol chemistry and physics. In the process,
the characteristics of the size spectrum of cloud droplets at cloud base
are determined by the physicochemical properties of aerosol and the water
vapour supersaturation, evolution of the latter being coupled to the
vertical velocity of the air. Owing to the fact that the radiative
properties of clouds and their ability to precipitate are both dependant
on characteristics of the size spectrum of cloud droplets, the description
of the activation process is of importance to the studies on
aerosol-cloud-climate interactions. A numerical experiment and observations
aimed at exploring the activation phenomenon are presented. The study is
carried out within the European Integrated Project on Aerosol Cloud Climate
Air Quality Interactions (EUCAARI).

An air parcel model with detailed treatment of aerosol microphysics offers
a simple yet robust technique for capturing cloud droplet activation in
a numerical experiment. A common practice in such models is to approximate
the size spectrum of the aerosol with a piecewise constant function, and to
reduce the partial differential equation for the evolution of the size
spectrum to a set of ordinary differential equations. This approach is
referred to as the moving-sectional technique or the method of lines (MOL).
One of the drawbacks of the moving-sectional method is its poor
representation of the size-spectrum shape in the region between the
unactivated aerosol mode and the activated cloud-droplet mode. An adaptive
spectrum refinement procedure that improves the performance of the method
is introduced and tested. Several examples of the model set-up are used to
demonstrate model capabilities. Model results are compared to those
without adaptivity revealing the uncertainties inherent to results obtained
with non-adaptive MOL.

In-situ observations of aerosol and cloud properties allowing studies of
cloud droplet activation were carried out by instrumented aircraft during
the EUCAARI Intensive Measurement Period At Cabauw Tower (IMPACT),
The Netherlands, in May 2008. EUCAARI-IMPACT was a month-long
pan-European effort to provide the state-of-the-art observational data
to the European atmospheric research community.A case study summarising
measurements of microphysical properties of aerosol and cloud droplets
during two research flights in polluted and pristine air masses over
The Netherlands and the North Sea, respectively, is presented.

● IFREE YES seminar
IFREE YES & LPSeismo seminar
Date: 27th July 2010 (Tue.) 16:00-17:00 Place: IT Build. 4F Room:403-404, Yokohama, JAMSTEC
Speaker: Masashi KAMOGAWA（Department of Physics, Tokyo Gakugei University）

Title: Sorry, no English title.
Abstract: Sorry, no English abstract.

References:
http://wwwsoc.nii.ac.jp/jepsjmo/cd-rom/2008cd-rom/program/pdf/S145/S145-004.pdf
http://pre.aps.org/abstract/PRE/v66/i1/e011902
http://pre.aps.org/abstract/PRE/v67/i2/e021109

● IFREE YES seminar
IFREE YES & LPSeismo seminar
Date: 29th June 2010 (Tue.) 15:00-17:00
Place: IT Build. 4F Room:403-404, Yokohama, JAMSTEC
Speaker : Ryosuke Ando (Active Fault and Earthquake Research Center, AIST)

15:00-16:00
Speaker: Tatsu Kuwatani, Kenji Nagata, Masato Okada, Mitsuhiro Toriumi(Graduate School of Frontier Sciences, University of Tokyo) Title: Sorry, no English title.
16:00-17:00
Speaker: Masato Okada (Graduate School of Frontier Sciences, University of Tokyo)
Title: Sorry, no English title.

● IFREE YES seminar
IFREE YES & LPSeismo seminar
Date: 23th March 2010 (Tue.) 16:00-17:00
Place: IT Build. 4F Room:403-404, Yokohama, JAMSTEC
Speaker : Ryosuke Ando (Active Fault and Earthquake Research Center, AIST)

Title: A slip pulse model with fault heterogeneity for low-frequencyearthquakes and tremor along plate interfaces

Abstract:
Deep low-frequency earthquakes (LFEs) and nonvolcanic tremor have
distinctive characteristics unlike those of regular earthquakes,
including strong anisotropy in their migration velocity and source
spectra that display 1/f decay. We show that a physics-based model can
explain these features in a simple framework with slip pulses
originating on fault heterogeneity and triggered by slow-slip events.

● IFREE YES seminar
Date: 26th February 2010 (Fri) 15:00 -
Place: IT Build. 4F Room:403-404, Yokohama, JAMSTEC

Speaker1: John Hernlund (U.C. Berkeley)
Title1: Dynamical Instability of Partially Molten Asthenosphere.

Speaker2: Christine Houser (U.C. Santa Cruz)
Title2: Seismic evidence connecting western Pacific volcanism to thermo-chemical structures in the core-mantle boundary region.

● IFREE YES seminar
Date: 29th January 2010 (Fri) 13:30-15:00
Place: IT Build. 5F Room:506, Yokohama, JAMSTEC
Speaker: Yasumitsu Maejima(Hydrospheric Atmospheric Research Center)

Title: Sorry, no English title.

Abstract: Sorry, no English abstract.