Tag Archives: lakes

1.17 x 10^8 and counting…

Ever wondered just how many lakes there are in the world? It turns out, a whole lot!

Scientists based at Uppsala University in Sweden surveyed more than 8000 high-resolution Landsat 7 [1] images to create the largest database of the world’s water bodies, to date. Their estimate: 117 million lakes (> 0.2 hectares) cover the earth, making up nearly 4% of its glacier-free surface area. Laid end to end, the shoreline of these numerous lakes would circle the globe 250 times!

To ensure a reliable analysis, the lakes included in the new global lakes database, GLOWABO, needed to be 2000 square meters or larger, an area nearly the size of two Olympic swimming pools. Even the larger lakes could be tricky to identify: mountain shadows, nearby vegetation, and cloudy water confounded the analysis so the researchers needed to design an algorithm which could untangle any visual uncertainty.

Global lakes databases, like GLOWABO, can help scientists estimate the amount of carbon stored in lake-bottom sediments, as well as the amount of greenhouse gases (like carbon dioxide and methane) lakes release into the atmosphere each year.

While Minnesota boasts more than 10000 lakes, its lakes make up only a fraction of the world's lakes, according to recent research by Verpoorter et al. 2014.  Source:   http://geology.com/satellite/cities/minneapolis-and-st-paul-satellite-image.shtml
The new global lakes database, GLOWABO, quantifies the total number of the world’s lake, including the more than 13000 lakes of Minnesota (the author’s home state), some of which are shown here in the Twin Cities’ chain of lakes. Source: http://geology.com/satellite/cities/minneapolis-and-st-paul-satellite-image.shtml

[1] Landsat is an Earth Resources Technology Satellite that was launched starting in 1972 to collect data and take remote images of the Earth. Earth-observing satellite missions are jointly managed by NASA and the U.S. Geological Survey.

 

Lake 3D Visualization Content Map

Draft November 10, 2011

Lake3D Viz Content Map articulates content main messages for the informal science education on freshwater water ecosystems and their stewardship. The users of the content map are developers and practitioners who create learning materials for visitors and the public. The ideas articulated in the map drives all the educational products including (but not limited to) the visualizations, tabletops, media and websites.

The top level of the map has 3 overarching key big ideas about fresh water ecosystems and their stewardship. All educational products engage the visitors and the public in these main messages.

Each of the big ideas is linked to a set of learning objectives that the educational products will address. The learning objectives simplify the ideas into various pathways that will result in conveying the message to the visitor.

In order to develop the educational product such as visualization or a table-top activity, the learning objectives are further expanded into a detailed list of categorized topics, similar to the index in a textbook. Each topic may be addressed in more than one educational product. For example, earthquakes and faulting are topics that are closely linked to the formation of lakes and the dynamics of its change. These topics can be address through the 3D visualization as well as through table-top interactives.

Big Ideas:

Idea 1: Water connects to water, land, air and life

Idea 2: Freshwater ecosystems are dynamic, complex and are constantly changing

Idea 3: Humans study, manage and impact freshwater ecosystems on local as well global scale Continue reading Lake 3D Visualization Content Map