The Hawaii-2 Observatory

Abstract

A permanent deep ocean scientific research facility-the Hawaii-2 Observatory (H2O)-was installed on the retired HAW-2 commercial submarine telephone cable in September 1998. H2O consists of a seafloor submarine cable termination and junction box in 5000 m of water located halfway between Hawaii and California. The H2O infrastructure was installed from a large research vessel using the Jason ROV and standard over-the-side gear. The junction box provides two-way digital communication at variable data rates of up to 80 kbit/s using the RS-422 protocol and a total of 400 W of power for both junction box systems and user equipment. Instruments may be connected by an ROV to the junction box at 8 wet-mateable connectors. The H2O junction box is a "smart" design, which incorporates redundancy to protect against failure and allows full control of instrument functionality from shore. Initial instrumentation at the H2O site includes broad-band seismometer and hydrophone packages.

Management and research applications of real-time and archival passive acoustic sensors over varying temporal and spatial scales

“…An increasing number of nonmilitary acoustic observatories are now operational in coastal areas (e.g. the ALOHA Ocean Observatory Network, Petitt et al 2002, Barnes et al 2007). These systems (1) allow real-time monitoring and localization of marine animals; (2) record continuously over broad frequency bandwidths; and (3) have no restrictions on data storage, data access or power supply.…”

Ionospheric remote sensing of the Denali Earthquake Rayleigh surface waves

“…These models are however severely limited by the non homogeneous distribution of stations and seismic sources. Only a few seismic stations have been deployed at the bottom of the oceans [e.g., Petitt et al , 2002], which cover about 70% of the Earth's surface, and only a few are permanently installed on islands, where they face generally large micro‐seismic noise levels. A second limitation, inherent to the phase or arrival time of surface waves, is related to the accumulation of the seismic information along the source to receiver path.…”

A Study of the Remote Control for the East China Sea Seafloor Observation System

“…Current communication fitting for seafloor observatories fall into two categories, wired communication and wireless communication, and the chosen ones differ in the specific type of seafloor observation system (Chen et al 2006). For instance, the Hawaii-2 Observatory (H2O) used serial communication and the RS422/232 protocol for a data path between junction box systems and underwater equipment in the local seafloor observatory (Petitt et al 2002). In contrast, the Monterey Bay Aquarium Research Institute (MBARI) Ocean Observatory System (MOOS) strives to maintain compatibility with development projects of both portable and cabled observatories in the large oceanographic community (Chaffey et al 2001;Akyidiz et al 2005), and enable remote communication with, on the one hand, observation data that are transmitted sequentially via buoys and satellites until arriving at the shore station for further centralized processing and, on the other hand, junction box subsystems that connect to the backbone cable and transfer data to the shore station through the optic fiber.…”