Seminar Schedule < Institute For Research on Earth Evolution

2011

● A Special All-IFREE seminar information

[This seminar was postponed.]

- Meeting for reporting IFREE research activity in H22 -
Date: March 22nd (Tue), 2011 1300-1800
Place: Miyoshi Memorial Hall, YOKOHAMA Institute

We are pleased to invite you to the All-IFREE Seminar, for an evaluation of the IFREE research activity in H22.

Schedule:

1300-1305	Opening address
1305-1315	Re-organization of IFREE from FY23
	-- Report of research activity in FY22 --
1315-1345		Recent progress in Nankai seismogenic zone studies and a future direction for constructing mechanical models
1345-1415		Formation of continents and fate of anti-continents
1415-1445		Origin of the HIMU reservoir and implications to mantle evolution
1445-1515		Simulation of mantle convection
1515-1530		Break
1530-1600		Understanding Earth's Deep Interior and Its Impact on the Surface
1600-1630		Structure and dynamics of the Earth's core
1630-1650		Development of marine observation instruments and analytical techniques
1650-1710		Development of analytical techniques and instruments for innovative solid Earth geochemical studies
1710-1730		Parallel-vector algorithms for particle simulations on shared-memory multiprocessors
	---------------------------------------
1730-1755	Discussion
1755-1800	Closing address
1830-2000	Party at guest-house of YES

● IFREE ALL seminar information
The 47th IFREE ALL seminar on February 18 (Fri), 2011.
Place: Miyoshi Memorial Hall, Yokohama institute (YES)
Time: 16:30-17:30 on February 18 (Fri)
Speaker: Natsue Abe (Subseafloor Dynamics Research Team)
Title: The MoHole: A Crustal Journey and Mantle Quest

Abstract:
The MoHole project, which will drills into an intact portion of oceanic
lithosphere,is a long-standing ambition of scientific ocean drilling.
The 2010 MoHole workshop* in Kanazawa followed from several scientific
meetings on ocean lithosphere drilling,which reached a consensus that a
deep hole through a complete section of fast-spread crust is a renewed
priority for the community. New deep drilling technologies now make it
possible to fulfill our aspiration to drill completely through intact oceanic
crust and into the upper mantle, and address a number of first-order
scientific goals: what is the geological nature of the Moho? How is the
oceanic crust formed at mid-ocean ridges, and what processes influence
its subsequent evolution? What are the geophysical signatures of these processes?
What are the interactions with the oceans and biosphere, and their
influence on global chemical cycles? What are the limits of life, and
the factors controlling these limits? What is the physical and chemical
nature of the uppermost mantle, and how does it relate to the overlying
magmatic crust? There must be more questions to be answered with
carrying out this project.

The selected MoHole target would ideally meet a suite of scientific
requirements including fast spreading rate, simple tectonic setting,
"normal" crustal seismic structure, and strong reflectivity of Moho.
Several technological constraints limit the range or possible sites,
including in particular the trade-off between seafloor depth, which
should be small enough to allow using mud re-circulating technologies,
and temperature at Moho/upper mantle depths, which should be low
enough (~≦250℃) to allow ultra deep drilling (> 6000m) in basement.
The workshop participants discussed three areas in the Pacific Basin:

1) the region around Site 1256

2) the eastern Pacific plate off Mexico

3) the eastern edge of the north Hawaiian arch

I will present the primary scientific target and explain why we choose the site
candidate in the seminar, and ask your opinion and contributions.

*The Kanazawa WS report (Ildefonse et al., 2010, Scientific Drilling: doi: 10.2204/iodp.sd.10.07.2010).

● IFREE ALL seminar information
The 46th IFREE ALL seminar on January 21 (Fri), 2011.
Place: Miyoshi Memorial Hall, Yokohama institute (YES)
Time: 16:30-18:00 on January 21 (Fri)
Speaker1: Yoshio Fukao (Reserch Director, IFREE)
Title1: Look into the Earth’s interior and look up into the ocean from the seafloor

Abstract1:
What can be seen when we look into the ocean upward and the solid Earth
downward equally from their interface using seismological means?
I select three topics in response to this question.
The first is a detection of unusual seismic events right beneath the long-term
BBOBS (BroadBand Ocean Bottom Seismometer) observational sites.
The data indicate that these unusual events occur along the decollement
zone in the Nankai Trough accretionary prism.
The second is a modeling of excitation of the Earth's hum (the Earth's
background free oscillations). The "hum" is excited by mechanical coupling
of ocean infragravity waves with the seafloor topography.
The third is a seismic imaging of the ocean internal tidal beam winded by
the Kuroshio current. The imaging is made using the reflection survey data
for the oceanic crust and mantle structure.
These examples imply the importance of collaboration with physical
oceanography to expand "ocean bottom seismology" to a wider concept
of "ocean seismology".

Speaker2: Mitsuhiro Toriumi (Earthquake and Tsunami research project for Disaster Prevention)
Title2: Vibrating plate, dimension regression and machine learning

Abstract2:
In the experiments of rock deformation under low temperatures, we see
commonly repeating signals ofhigh frequency phonons generated from
high strain zones. The signals emission occurs at the level of previous strain
or stress and this phenomenon is called as Keizer effect. These signals are
considered to be derived from micro scale crack formation. Thus, the elastic
wave signals density should indicate the state of strain and stress of the
particular region of the deforming sample.
In the natural case, micro seismic activity can be commonly observed in
the plate boundary zones, involving crust of the island arc and subducting
slab in the subduction boundary and oceanic crust of the divergent boundary.
From the relationships of seismic magnitude and size of shear crack of the
seismic signals, shear cracks of M1-2 should have 1-10 meters length with
several ten microns displacement. Theses spike signals reveal the strain
states of the earth interior as like as Keizer effect and the inhomogeneous
occurrence and irregular time series indicate the characteristics of
mechanical coupling degree in the crust and mantle.
In this talk the author will show the researches of the mechanical states
of the subducting plate and overriding crust by means of dimension
regression and machine learning methods for applying PSP and PP.
It leads that the periodic change of the weakly ordered strain patterns
of the plates.
Further, Beysian inversion method using Markov random field model of
fluid geometry and volume fraction in the wedge mantle will be introduced
in this talk. It suggests that aspect ratios can be actually separated from
volume fraction of the fluid.
Finally, I will talk about the next strategy and tactics of the IFREE
researches which yield new fields of the systems earth science having
huge high dimensional informations acquisited from shipping,
ocean bottom obsevatories, drilling, and geochemical observations,
modeling and experimental researches.