Project

Introduction

  The Institute of Earth Sciences first pondered the question of how to develop an OBS program in the advisory meeting in December 2000.  Although IES pioneered the installation of seismic network in Taiwan, extending its observational force into the ocean has not been perceived as the institute’s responsibility.  However, prompted by the ever mounting need by the community to investigate the offshore earthquakes and to explore deeper and broader tectonic regimes (Fig. 1 & 2), IES decided to take a leadership role in launching a sustainable project on OBS instrumentation and research in Taiwan.  After a lull period of planning and preparation, our engineers joined the WHOI OBS lab in 2005 to co-build a small array of broadband OBSs as a pilot project.  Table 1 lists the milestone events during 2000-2006.  Typhoon Lee’s (then the IES director) inspiration in the early stage was crucial in laying out the blueprint of the project.

 

Table 1
2000 Advisory committee suggested an evaluation (Dec)
2001 Academia Sinica headquarters granted seed money
2002 Preliminary planning; Spahr Webb visited IES (May)
2003 OBS international workshop (March)
      OBS team visited WHOI (Sep)
2004 An MOU signed with WHOI to build OBSs (May)
2005 Deployment practice, PLUME at Hawaii (Jan)
         Construction of OBSs, phase I (Apr-May)
         Construction of OBSs, phase II; 4 units completed (Sep)
         Shallow water test (Dec)
2006 1st deployment, Sept 1-4

 

Development strategy

  To pursue a sustainable project that aims at long-term scientific returns, we co-built the instruments from scratch in the WHOI’s OBS lab in order to attain basic know-how and hands-on experience. This approach contrasts the common practice of purchasing turn-key solutions that has prevailed in the academies of Taiwan in the past. The collaboration between IES-AS and WHOI was a great success due to two factors: the dedication of the motivated and skillful IES engineers and the generosity of the WHOI mentors. During the lab work, there were occasions in which IES engineers were able to feedback their experience to the WHOI counterparts, making the collaboration much healthier than a unilateral commercial deal.

  The broadband instrument was our choice to kick off the project. Since the 1990s, high-frequency OBSs have been acquired by Taiwan from the US and France to conduct active-source experiments as well as aftershock relocating; yet, IES will not repeat this scheme of research but instead set goals to (1) fully utilize the rich frequency content of an earthquake to address more challenging problems concerning the dynamics of the region as well as to (2) exercise engineering innovation in the creation and use of instruments.

  IES realizes the importance of tapping domestic talent and resources. In 2006, a 3-year NSC integrated project was started and joined by other universities traditionally strong in marine geophysics to execute the deployment and recovery.  Follow-up projects with new scientific goals will continue in 2009.  In 2008, an inter-institutional group of interest began to take shape to share resources and orchestrate engineering efforts in experimenting with new technologies in OBSs.  A short-term objective of this group is to test devices to increase the success rate of instrument recovery and data retrieval.  The key members of the group, in addition to IES, are IUT-NSYSU, IO-NTU, and NTUT (Table 2).  The success of the project will hinge in how well the community resources are integrated under a focused goal.

 

Table 2
IES-AS, Institute of Earth Sciences, Academia Sinica
IUT-NSYSU, Institute of Undersea Technology, National Sun Yat-sen University
IO-NTU, Institute of Oceanography, National Taiwan University
NTUT, National Taiwan University of Technology