Wildebeest Migration in the Serengeti Region - Image of the day, July 1st 2019

This image was taken using a GeoEye-1 satellite with a 0.5 m resolution sensor. No date is given as to when the image was captured but the image was taken in Kenya. The purpose of the image is to observe wildebeest migration. Although the image source does not specify when the migration occurs, it is well known that wildebeest migration usually occurs between June and October. However, this migration period is not definitive because seasons change may affect it. A great number of wildebeest leaves the Serengeti region of Tanzania when the rainy season ends and plains have dried out. During that period of time, the wildebeest herd crosses the Masai Mara river in Kenya and stays until October, at which point it crosses the river again to return to the Serengeti region. The image might be important to monitor wildebeest population growth or decline over time and it is also important to observe grazing patterns during this migration.

Image Source:
https://www.satimagingcorp.com/applications/environmental-impact-studies/wildlife-and-marine-conservation/wildlife-monitoring/

Image of the day, June 30, 2019: Water Shortage in India

    This pair of satellite images were taken by NASA's EO-1 respectively on May 31, 2018 and June 19, 2019 to compare the conditions of reservoirs in Chennai, the sixth largest city of India. Basically, critical drought attached most parts of India, about 2/3 of reservoirs are getting drier due to the less amount of precipitation, heatwaves, and water management. The Red Hill Lake (central above) is becoming smaller and shallower than one year ago, the same phenomenon occurs on most visible reservoirs in the city. From a macro view, this image set indicates how climate change worsen water shortage in tropical countries such as India; on the other side, it also provides reliable data by satellite to help relative departments make possible solutions.

Chernobyl Nuclear Power Plant, week of July 1st

This image (2016) displays the Chernobyl Nuclear Power Plant, 30 years after the nuclear disaster of 1986. The facility at the center of the image is the power plant itself, and the reflective cylindrical figure is the New Safe Confinement encasing reactor No. 4, the site of the core explosion that spewed high levels of radioactive and airborne isotopes into the surrounding land and atmosphere. The purpose of this was to halt the release of contaminants into the environment for nuclear decommissioning. Manmade channels run through the facility originating from a large lake that once served as a cooling pond for reactor-related activities. Agricultural plots are discernible along the plant’s outskirts, and although they have since been abandoned, vegetation continues to grow densely. It is interesting to see how flora and fauna have thrived here following nuclear contamination. Recent studies found that wildlife flourished in the exclusion zone; it was thought that the accident would leave surrounding areas devoid of significant wildlife for many decades. However, in only three decades it has become a refuge for brown bears, bison, wolves, lynxes, Przewalski horses, and 200+ bird species.

https://www.intelligence-airbusds.com/en/5751-image-gallery-details?img=39546#.XRP1yS2ZN0s

https://earthobservatory.nasa.gov/images/39679/chernobyl-ukraine

http://theconversation.com/chernobyl-has-become-a-refuge-for-wildlife-33-years-after-the-nuclear-accident-116303

Image of the Day June 24, 2019

It seemed perfect that this was the Image of the Day from June 24, 2018 on the NASA Earth Observatory website. 

This is a daylight true color image and a thermal image taken 3 weeks after the eruption of Volcan de Fuego in Guatamala. Images were taken using Landsat 8. Scientists are studying this imagery for a number of reasons, including ongoing learning about the behavior of volcanoes and lahars, and the potential for disaster response during night time events. However, as the article points out, the nighttime response would be limited to a satellite being in the correct position with the correct weather conditions, so is not a system that could be relied on as a primary source of information. 

Link the the article:

https://earthobservatory.nasa.gov/images/92354/heat-lingers-from-fuegos-deadly-pyroclastic-debris-flows

Remote Sensing Can Measure Volcanoes Grow and Shrink

The image shows subtle expansion of Kilauea, which implies that magma is applying pressure from underneath. The image has concentric rings of color to show whether the volcano's radial movement is toward or away from the sensor and by how much, with three distinct rings equating to three half-wavelengths of 1.65 cm for a movement of 4.95 cm over nearly two months. This kind of information is especially important in places like Hawaii and places on the Pacific ring of fire, like Japan and Indonesia, where people live by volcanoes. 

https://www.hawaiitribune-herald.com/2019/06/23/features/volcano-watch-reading-the-rainbow-how-to-interpret-an-interferogram/

As for the interferometry, I was displeased with the article's explanation for it so I like the way the following site describes it. Basically, two beams of light traveling the same distance through the same medium should be moving at the same speed. Therefore, the return signals, or lack thereof when a single beam is split and sent in two different directions before coming back and effectively neutralizing each other's waves, should arrive to a sensor at the same time. However, when something causes a beam to slow down, then the difference can be recorded.

https://www.ligo.caltech.edu/page/what-is-interferometer

Image of the Day 6/24/19: South Korean Seaweed Aquaculture

This image was taken on January 31, 2014 and displays seaweed fields along the southern coast of South Korea. Seaweed is grown along this coast through aquaculture farming techniques and contributes to 90% of South Korea’s total seaweed crop. The seaweed in this farm is grown on ropes held close to the surface by buoys, allowing for sufficient sunlight during changing tides. This rope technique also accounts for the straight sections of seaweed crop displayed as dark squares in the image. Additionally, the seaweed’s ability to grow in these coastal waters means these aquaculture farms do not require fresh water or fertilizer; making them more sustainable than land-based farms. Most aquaculture in the United States consists of fish production, so this satellite image presents a unique view of vegetative aquaculture methods uncommon to our agricultural practices.

https://earthobservatory.nasa.gov/images/85747/seaweed-farms-in-south-korea