In other words, sequence signatures have not yet been surveyed systematically and objectively.

But Mr. Andreasen said few commercial ships used the area, and "it has never been systematically surveyed."

Land was to be systematically surveyed into square "townships", six miles (9.656 km) on a side created by lines running north-south intersected by east-west lines.

However, most arid and semi-arid zone lakes have not been systematically surveyed or assessed for cultural heritage significance.

The island was systematically surveyed by Pyotr Pakhtusov and Avgust Tsivolko in the early 1830s.

The vegetation of Belize was first systematically surveyed in the 1930s.

The plant thrives in the verdant Balsas River basin, 150 miles west of the Tehuacan valley, but the area has never been systematically surveyed.

Subsequently the areas listed in the society's masterplan were systematically surveyed and reports prepared.

The floodplains have once been systematically surveyed when flooded (in 2001), when they probably contained over a million waterbirds.

Land was to be systematically surveyed into square townships, six miles (9.656 km) on a side.