0 views 2018-09-05 22:29:33
According to Reuters, an earthquake of magnitude 6.2 struck off an eastern Indonesian province on Tuesday (Aug 28), the US Geological Survey said. There were no immediate reports of damage or casualties from the quake, which hit at a depth of 10km about 100km southeast of Kupang, capital of the province of East Nusa Tenggara. Indonesia has been rocked by a string of deadly earthquakes, particularly on Lombok island, which has left 555 people dead and hundreds of thousands homeless. The picturesque island next to holiday hotspot Bali was hit by two deadly quakes on Jul 29 and Aug 5. It was shaken by a string of fresh tremors and aftershocks, with the strongest measuring 6.9 magnitude. About 390,000 people remain displaced after the quakes, Indonesia’s disaster agency has said. Aid organisations have vowed to step up humanitarian assistance on the island as devastated residents struggle in makeshift displacement camps.
Indonesia, one of the most disaster-prone nations on earth, straddles the so-called Pacific “Ring of Fire”, where tectonic plates collide and many of the world’s volcanic eruptions and earthquakes occur. In 2004 a tsunami triggered by a magnitude 9.3 undersea earthquake off the coast of Sumatra in western Indonesia killed 220,000 people in countries around the Indian Ocean, including 168,000 in Indonesia.
As one of the natural disasters that cause great damage to people’s lives and property, the earthquake is a vibration caused by the rapid release of energy from the earth’s crust, and a natural phenomenon of seismic waves generated during this period. Earthquakes can often cause fires, floods, toxic gas leaks, the spread of bacteria and radioactive materials, and may cause secondary disasters such as tsunamis, landslides, collapses, and ground fissures, causing extremely serious casualties and property damage. According to statistics, there are more than 5 million earthquakes on the earth every year, which means thousands of earthquakes occur every day. Most of them are too small or too far away to be felt. But there are about ten or twenty earthquakes that can cause serious harm to human beings and about one or two earthquakes that can cause particularly serious disasters. In order to protect the safety of life and property, people must understand the earthquake and must use a seismograph to record it. Thousands of various seismographs are operating in the world to monitor the movements of the earthquake day and night.
Can scientists predict earthquakes?
No, and it is unlikely they will ever be able to predict them. Scientists have tried many different ways of predicting earthquakes, but none have been successful. On any particular fault, scientists know there will be another earthquake sometime in the future, but they have no way of telling when it will happen——USGS. However, humans can monitor earthquakes, warn of the onset of earthquakes. What human beings should do more is to quickly monitor the occurrence of earthquakes and where the sources are, in order to inform people to respond quickly. Warnings of one minute or even tens of seconds can greatly reduce casualties and property losses.
So what is the traditional way to monitor earthquakes? The traditional way of detecting earthquakes is mainly to rely on seismic monitoring stations to observe underground seismic activities in various places, and finally form a national seismic observation network. The seismic monitoring station mainly uses the feature of seismic P wave which transmits faster than the S wave. When the P wave is detected by the seismic network, it will immediately release the seismic information to the potentially affected areas through radio, television, mobile phones, and the Internet to Inform the public how long it takes for the S wave to arrive, and earn valuable time of a few seconds to tens of seconds for the people not in the epicenter. Comparing the 2008 Wenchuan Earthquake and the Tangshan Earthquake in 1976, it was this short tens of seconds that allowed the people who were not in the epicenter to have a breathing time, allowing the troops to quickly and accurately reach the disaster area and launch rescue activities. The meaning of these tens of seconds is extraordinary. In addition to the rapid determination of the epicenter, the magnitude and the depth of the earthquake, and the rapid feedback to the relevant disaster relief departments, the role of the seismic monitoring station provides real-time data research for the seismic research.
The USGS Seismic Monitoring Facility at Guantanamo
As people’s understanding of the dangers of earthquakes continues to deepen, the people and the country are eager to hope that the development of modern science and technology can help people predict the occurrence of earthquakes. Today it is no longer an unreachable thing for human beings to predict the occurrence of earthquakes. Geophysicists and geographers have discovered that before the earthquake, the friction of the rock under ground stress produces electromagnetic radiation, and the cutting of magnetic lines of force causes the earth’s magnetic field to distort. A large number of statistical results have proved that space electromagnetic disturbance has obvious correlation with earthquake occurrence. Therefore, by using the satellite which has the space electromagnetic detection capability to detect the ionospheres’ space electromagnetic environment, it is possible to effectively understand the crustal activity before the earthquake and even predict the occurrence of the earthquake. Although it is still too early to discuss earthquake predictions, the accumulation of China and the world’s scientific community in this field is expected to overcome this problem in the future.
So what is the advantage of the satellite “eye of the sky” in the field of earthquake prediction compared to the traditional earthquake monitoring station?
1. Due to the construction of the seismic monitoring station and the monitoring environment, the station needs to be built far away from the city, such as the deep forest, to avoid the noise of humans’ activity. This has led to the problem that the distribution of seismic monitoring stations in various regions is too scattered to conduct monitoring of large-scale underground seismic activities and the high cost of construction and maintenance. Compared with the traditional seismic monitoring stations, using satellites to monitor earthquakes greatly compensates for the shortcomings of ground seismic monitoring stations. Satellites can monitor large areas of land from outer space without geographical constraints, and their launch and maintenance costs are much lower than those of seismic monitoring stations.
2. Due to the continuous expansion of urban land use and the increasing construction of national infrastructure, this will inevitably affect the normal monitoring of seismic monitoring stations. According to statistics, there are about 1,400 earthquake monitoring stations in China, of which about 700 are professional stations. About 40% of the 1,400 stations are disturbed by the surrounding environment, the observation effect is extremely unsatisfactory, and 20% has suffered considerable damage, and must be re-elected and relocated. Compared with seismic monitoring stations that are susceptible to human activities, satellites’ monitoring environment is less susceptible to impact, thus ensuring the accuracy and authenticity of seismic monitoring data.
3. Earthquake monitoring stations routinely monitor data on various types of underground activities in various regions, including earthquakes, geomagnetism, topographic changes, and crustal movements. From the perspective of the country’s overall disaster prevention and mitigation, most underground activities have little impact on people’s lives. The earthquake prediction satellites are loaded with high-precision magnetometers, inductive magnetometers, electric field detectors, plasma analyzers, and high-energy particle detectors, which can realize the monitoring of space electromagnetic field, ionospheric plasma and high energy particles in low earth orbit. Its monitoring target is mainly earthquakes of magnitude 6 or above in the world, because the magnitude 6.0 earthquake will release about 100,000 amps of current, and earthquakes of magnitude 7.0 and above will release more than one million amps of current. Therefore, the satellite can accurately obtain the abnormal changes of the electromagnetic environment of the ionospheric space before the earthquake of magnitude 6 or above in a large area. Moreover, high-density electromagnetic pulses unusually appear in the hours to days before the earthquake, so the earthquake information can be obtained by satellite monitoring several days before the earthquake. In this way, through the mutual cooperation between satellite and seismic monitoring stations, it is hoped that human beings will accurately predict the earthquakes in the target area in the future.。
In the field of satellite monitoring earthquakes, countries all over the world are actively exploring. Internationally, satellite-based space electromagnetic detection has been ongoing since the 1950s. Among them, China, the United States, Russia, France, etc. have launched a number of satellites around the ionospheric space electromagnetic environment.
China’s first electromagnetic monitoring test satellite “Zhang Heng-1” was successfully launched on February 2, 2018 at the Jiuquan Satellite Launch Center. “Zhang Heng-1” can detect the electromagnetic anomalies in the space before the earthquake, and is mainly used for the study of the mechanism of earthquake inoculation and the preliminary technical reserve for the establishment of the earthquake monitoring system in the future. This satellite realizes a revisiting of the same place on the earth every five days. The observation area can cover the earth’s north and south latitudes within 65 degrees. The key observation areas cover the whole land of China, about 1000 kilometers around the land and two major seismic zones around the world. “Zhang Heng-1” is the first star of China’s geophysical field exploration satellite program. It has a vital meaning in promoting the application of integrated spatial information research, accelerating the development of “Zhangheng-2” satellite and the planning and demonstration of the follow-up geophysical field detection satellite, and improving the information acquisition capability of China’s global geophysical field.
New ESA technology-testing CubeSat to launch with China’s seismo-electromagnetic satellite in February
The US Department of Defense launched the Defense MetroSatellite Plan (DMSP) project in the mid-1960s to provide information on the cloud height and types, land and surface temperature, water vapor, ocean surface, and space environment. In 1978, the National Oceanic and Atmospheric Administration and the NASA launched TIROS-A satellite increased the detection of space high-energy particles (electrons and protons above 30 keV). The satellite was incorporated into the NOAA series of polar orbiting satellites (mainly used for weather monitoring and forecasting applications) and was numbered NOAA-6. In April 1993, the United States launched the ALEXIS satellite. The total weight is 113kg, the orbital height is 750-850km, the inclination is 70°, and the star load is low-energy X-ray imaging sensor array and VHF band EMP receiver BLACKBEARD. Among them, the main task of BLACKBEARD is to measure the propagation effect and dispersion effect of ionospheric lightning pulse (LEMP) and EMP emitted by LAPP, and detect the LEMP signal from the original recorded 25-100MH bandwidth artificial carrier noise VHF signal. In August 1997, the United States launched the FORTE satellite with a satellite altitude of 768-810 km and a 70° dip, inheriting and improving BLACKBEARD detection technology, and developing the V sensor system for automatic and reliable detection of NEMP in complex electromagnetic noise environments. In June 2003, the United States launched the QUAKESAT satellite. The scientific goal of the satellite is to study the relationship between ELF magnetic field signals and seismic rock rupture, and to predict seismic activity.
Artist’s view of the deployed QuakeSat nanosatellite
Russia launched the COMPASS-I satellite and the COMPASS-II satellite in December 2001 and May 26, 2006, respectively. The COMPASS-I satellite has an orbital height of 830km and an inclination of 98.85°. The payload is equipped with a low-frequency wave analyzer (frequency range: 8 Hz to 20 kHz), a high-frequency wave analyzer (frequency range: 100 kHz to 15 MHz), particle detector, GPS receiver, UHF transmitters, whose main scientific goal is to explore and test earthquake prediction techniques. The COMPASS-II satellite orbit has a height of 488 × 401 km and a dip of 78.9 °. The payload is configured as a radio frequency analyzer, a low frequency wave (VLF/ELF) combined detector, a dual frequency transmitter, a GPS receiver and a particle detector. The scientific goal of the satellite is to study precursors such as ionospheric electromagnetic and plasma disturbances associated with earthquakes, volcanoes and other large-scale natural disasters; to develop large-scale observations by using microsatellites; to study the dynamic mechanism of the atmosphere, the ionosphere, and the Earth’s magnetosphere.
ESA launched the SWARM satellite constellation on November 22, 2013. The satellite constellation uses a strategy in which three satellites are distributed across three different polar orbits. The two satellites have an initial height of 460km and the third satellite has a height of 530km. The payload includes a vector magnetometer, a scalar magnetometer, an electric field meter, an accelerometer, a GPS receiver and a laser corner reflector. The scientific goal of the constellation is to study geo-nuclear dynamics, geo-generator processes and nuclear-coupling coupling, lithospheric magnetic fields and their geological background, mantle conductivity, magnetic field characteristics associated with ocean currents, and the effects of the Sun’s Earth system.
The three identical satellites were launched together on one rocket in 2013.
From the electromagnetic satellite programs abroad, after the implementation of the technical verification, planning a constellation plan with multiple satellites to observe has become a development trend. Because during a period of time before and after a major earthquake, the number of times a single satellite flies over the epicenter of the earthquake is very limited, and the time of each sweep is very short, so the observation data available is very little. In addition, a single satellite is also affected by interference factors, so it is difficult to judge the time, location and intensity of the earthquake based on the data obtained by a single satellite. Therefore, to achieve the purpose of earthquake prediction, it is not enough to use only one satellite. It is necessary to establish a comprehensive satellite constellation composed of multiple types, multiple means and multiple satellites. The constellation observation by a constellation of multiple electromagnetic satellites of the same kind, or combined with satellites such as infrared remote sensing, gravity, SAR or InSAR, will be the development trend of seismic electromagnetic satellites in the future.
Since satellites can play such a huge role in the face of natural disasters, as the world’s leading commercial satellite company, Changguang Satellite Technology Co., Ltd. also hopes to accelerate the development of seismic electromagnetic satellites by virtue of its own advantages. Changguang Satellite Technology is a world’s leading commercial satellite producer, operator and remote sensing information service provider, founded on December 1st, 2014. Changguang Satellite company is equipped with a technical personnel of 400 high-level technicians specialized in related areas, with 78% having a master degree or above, 6 doctoral supervisors and 7 master ones, which can provide satellite assembly and components, optical payload, satellite ground application system, satellite detecting equipment; satellite tracking, controlling and monitoring systems; remote sensing information and device maintenance services; technical consultation and services as well as other high-end customized products and services. Although Changguang Satellite’s field of expertise is in optical remote sensing, its R&D, manufacturing and maintenance levels are still in the leading position in the world. Changguang Satellite hopes to contribute to the development of seismic electromagnetic satellites in terms of basic R&D and support, and contribute to human prediction of earthquakes.
This is a high-precision satellite attitude control simulation system developed by Changguang Satellite.
This is the ZM-1500 vacuum experimental equipment developed by Changguang Satellite Company. It is mainly used to simulate the complex environment such as vacuum and heat experienced by the satellite single unit components in the rail.