Está a começar a ambiciosa expedição científica Chikyu Hakken, durante a qual nos próximos anos se vai tentar perfurar a crosta terrestre até aos 7 mil metros para recolha de amostras e colocação de sensores sísmicos. O local da perfuração será no mar ao largo do Japão.
Muita informação sobre a expedição, objectivos e tecnologia podem ser encontrados no site oficial:
http://www.jamstec.go.jp/chikyu/eng/index.html
CHIKYU Expedition Status:
http://www.jamstec.go.jp/chikyu/eng/CHIKYU/status.html
Muita informação sobre a expedição, objectivos e tecnologia podem ser encontrados no site oficial:
http://www.jamstec.go.jp/chikyu/eng/index.html
First Access to the Megathrust Earthquake Zone
Earthquakes, especially those at subduction zones, are among the greatest natural hazards on the planet. The Sumatran earthquake and Indian Ocean tsunami of 2004 demonstrated to the world how devastating these events can be. To learn more about how and why earthquakes and tsunamis occur, the Integrated Ocean Drilling Program (IODP) explores the geology below the seafloor to study Earth processes that evolve over time, ultimately causing violent, unpredictable natural disasters.
The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is a complex ocean drilling project that will be conducted over several years with multiple expedition teams of scientists from all around the world. NanTroSEIZE attempts for the first time to drill, sample, and instrument the earthquake-causing, or seismogenic portion of Earth’s crust, where violent, large-scale earthquakes have occurred repeatedly throughout history.
The Nankai Trough is located beneath the ocean off the southwest coast of Japan. It is one of the most active earthquake zones on the planet. The plan for NanTroSEIZE includes drilling, below the ocean, very deep into the Earth to observe
earthquake mechanisms. Samples will be collected in order to study the frictional properties of the rock and sensors are to be installed deep beneath the sea floor to record earthquakes up close. The sensors and sample data are expected to yield insight into the processes responsible for earthquakes and tsunami. The data may shed light on how water and rock interact in subduction zones to influence earthquake occurrence.
EXPEDITION STAGES
Stage 1 (USFY 2007-2008)
Logging While Drilling (LWD) at all the Stage 1 sites.
Shallow branching faults and tectonostratigraphy of the Kumano forearc basin.
Coring of the incoming sediments and prism toe.
Stage 2
Stage 2 expeditions will drill the first of two planned deep riser holes using the drill ship Chikyu, targeting the megasplay fault zone at 3,000–3,500 meters below the seafloor for the first time in the history of scientific ocean drilling.
Stage 3
Stage 3 is a very challenging expedition that will focus on drilling 5,500–6,000 meters deep into the seismogenic zone and across the plate interface into the subducting crust. Once drilling is complete, an initial monitoring system will be deployed in the borehole. This monitoring system shall remain in place for one to two years, while the "final" long-term monitoring package is readied.
Stage 4
Stage 4 will install long-term observatory systems into the two ultra-deep boreholes. In Japan, a seafloor fiber-optic network for seismic monitoring and other applications is proposed for deployment in the Kumano Basin region. One exciting possibility is that the NanTroSEIZE boreholes ultimately could be connected to this network in Stage 4, allowing real-time access to earthquake data.
CHIKYU Expedition Status:
http://www.jamstec.go.jp/chikyu/eng/CHIKYU/status.html