World Hydrography Day 21 June

The International Hydrographic Organization celebrates World Hydrography Day every year on 21 June. World Hydrography Day is an opportunity to increase public awareness of the vital role that hydrography plays in everyone’s life. The theme for this year’s World Hydrography Day, which is also the 94th anniversary of the establishment of the IHO, is: Our seas and waterways - yet to be fully charted and explored.

The theme concentrates on the fact that much of the world’s seas, oceans and navigable waters remain unsurveyed. The theme is intended to raise public awareness that, for example, there are higher resolution maps of the Moon and Mars than for many parts of our seas and coastal waters.

Recent deep sea searches for missing aircraft have highlighted the situation to some extent - but it has not made a huge impact on the public or the political psyche. Sadly, mankind’s limited knowledge of the deep-sea region is mirrored by a similar lack of detailed knowledge for a very large proportion of the world’s coastal waters, too - where the development of the so-called blue economy is proceeding apace.

Knowing the depth and the shape of the seafloor and all the hazards that lie on it is increasingly important because Man is turning increasingly towards the sea and oceans for resources. The seas and oceans are now acknowledged as major contributors to the world economy and well-being. Over 90% of the world’s trade travels by sea. In addition, the seas and oceans, including the seabed and the sub-seabed, represent a vast resource for food, mineral resources, energy, water, bio-medicines and infrastructure. The oceans and the way the water moves and behaves are major influences on weather and climate. The shape and the depth of the seafloor have a significant impact on how sea level rise, storms and tsunamis affect the coastline.

The rapid growth and development of the blue economy makes knowing the depth of the seas and oceans more important than ever before. But, less than 10% of the world’s oceans have been systematically surveyed - the depth measurements that we do have are often tens or hundreds of kilometres apart. Along many coasts the state of affairs is little better. Ships cannot use new routes or visit new places. Trying to establish sustainable maritime activities in unsurveyed areas is unworkable.

The theme for 2015 is also providing the IHO with the opportunity to encourage innovative supplementary data gathering initiatives to help obtain more useful depth data. This includes crowdsourcing using existing ships and ship’s equipment, and the analysis of multi-spectral satellite imagery in areas where the water is clear enough - so-called satellite-derived bathymetry. These methods are not intended to replace more accurate and thorough hydrographic surveys using specialist ships and equipment, but to provide useful depth information where otherwise there is none.

Crowdsourcing for More Depth Data
As part of helping to improve our knowledge of the sea, the IHO operates the Data Centre for Digital bathymetry (IHO DCDB). The IHO DCDB is the principal web-based data store that provides access to most of the existing depth measurements for the ocean. Some of this data can be downloaded directly online; other data and metadata can be identified and then obtained from other sources.

The IHO DCDB is currently undergoing an upgrade to make it the world portal for the upload and download of so-called Crowd-Sourced Bathymetry (CSB). It will then be a resource for everyone. CSB will be collected by ships and boats using their navigation echo sounders during their normal voyages across the sea and along the coastline. Harnessing the collecting power of all mariners is an efficient way of obtaining depth data where there is currently no data or the data is uncertain.

Retrieving ‘lost’ Data
The IHO is also encouraging scientists and industry to look in their vaults and archives for depth data that has already been collected and could be added to the world collection or made discoverable through the DCDB portal. Data is often collected by industry or by the scientific community for a particular purpose, but once used, it is most often forgotten. That data, regardless of its quality, is still useful to others - especially when no other data exists.