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1968 Illinois Earthquake
The 1968 Illinois earthquake (a New Madrid event) was the largest recorded earthquake in the U.S. Midwestern state of Illinois. Striking at 11:02 a.m. on November 9, it measured 5.3 on the Richter magnitude scale, Richter scale. Although no fatalities occurred, the event caused considerable structural damage to buildings, including the toppling of chimneys and shaking in Chicago, the region's largest city. The earthquake was one of the most widely felt in U.S. history, largely affecting 23 states over an area of . In studying its cause, scientists discovered the Harrisburg, Illinois#Cottage Grove Fault System, Cottage Grove Fault in the Southern Geology of Illinois#Illinois Basin, Illinois Basin. Within the region, millions felt the rupture. Reactions to the earthquake varied; some people near the epicenter did not react to the shaking, while others panicked. A future earthquake in the region is extremely likely; in 2005, seismologists and geologists estimated a 9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoseismal Map
In seismology, an isoseismal map is used to show Contour line, countour lines of equally felt seismic intensity, generally measured on the Modified Mercalli scale. Such maps help to identify earthquake epicenters, particularly where no seismometer, instrumental records exist, such as for historical earthquakes. They also contain important information on ground conditions at particular locations, the underlying geology, radiation pattern of the seismic waves, and the response of different types of buildings. They form an important part of the macroseismic approach, i.e. that part of seismology dealing with noninstrumental data. The shape and size of the isoseismal regions can be used to help determine the Seismic scale#Magnitude scales, magnitude, Focus (earthquake), focal depth, and focal mechanism of an earthquake. History The first known isoseismal map was produced for the 1810 earthquake in Mór in Hungary, and published by Kitaibel and Tomtsányi in 1814. The first, six-level i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicenter
The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Determination The primary purpose of a seismometer is to locate the initiating points of earthquake epicenters. The secondary purpose, of determining the 'size' or magnitude must be calculated after the precise location is known. The earliest seismographs were designed to give a sense of the direction of the first motions from an earthquake. The Chinese frog seismograph would have dropped its ball in the general compass direction of the earthquake, assuming a strong positive pulse. We now know that first motions can be in almost any direction depending on the type of initiating rupture ( focal mechanism). The first refinement that allowed a more precise determination of the location was the use of a time scale. Instead of merely noting, or recording, the absolute motions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loyola University Chicago
Loyola University Chicago (Loyola or LUC) is a Private university, private Society of Jesus, Jesuit research university in Chicago, Illinois, United States. Founded in 1870 by the Society of Jesus, Loyola is one of the largest Catholic Church, Catholic universities in the United States. Its namesake is Saint Ignatius of Loyola. Loyola's professional schools include programs in medicine, nursing, and health sciences anchored by the Loyola University Medical Center, and the Loyola University Chicago School of Law. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Comprising thirteen colleges and schools, Loyola offers more than 80 undergraduate and 140 graduate/professional programs and enrolls approximately 17,000 students. Loyola has six campuses across the Chicago metropolitan area, as well as a campus in Rome. Another guest program in Beijing was closed in 2018. The flagship Lake Sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contiguous United States
The contiguous United States, also known as the U.S. mainland, officially referred to as the conterminous United States, consists of the 48 adjoining U.S. states and the District of Columbia of the United States in central North America. The term excludes the only two non- contiguous states and the last two to be admitted to the Union, which are Alaska and Hawaii, and all other offshore insular areas, such as the U.S. territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands. The colloquial term ''Lower48'' is also used, especially in relation to Alaska. The term The Mainland is used in Hawaii. The related but distinct term ''continental United States'' includes Alaska, which is also on North America, but separated from the 48 states by British Columbia in Canada, but excludes Hawaii and all the insular areas in the Caribbean and the Pacific. The greatest distance on a great-circle route entirely within the contiguous U.S. i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1812 New Madrid Earthquake
Year 181 ( CLXXXI) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Aurelius and Burrus (or, less frequently, year 934 ''Ab urbe condita''). The denomination 181 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Imperator Lucius Aurelius Commodus and Lucius Antistius Burrus become Roman Consuls. * The Antonine Wall is overrun by the Picts in Britannia (approximate date). Oceania * The volcano associated with Lake Taupō in New Zealand erupts, one of the largest on Earth in the last 5,000 years. The effects of this eruption are seen as far away as Rome and China. Births * April 2 – Xian of Han, Chinese emperor (d. 234) * Zhuge Liang, Chinese chancellor and regent (d. 234) Deaths * Aelius Aristides, Greek orator and writer (b. 117) * Cao Jie, Chinese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fault Plane
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep. A ''fault plane'' is the plane that represents the fracture surface of a fault. A ''fault trace'' or ''fault line'' is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geological maps to represent a fault. A ''fault zone'' is a cluster of parallel faults. However, the term is also used for the zone of crushed rock along a single fault. Prolonged motion along closely spaced faults can blur the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Mechanism
The focal mechanism of an earthquake describes the Fault (geology)#Slip.2C heave.2C throw, deformation in the Hypocenter, source region that generates the seismic waves. In the case of a Fault (geology), fault-related event, it refers to the orientation of the fault plane that slipped, and the slip Euclidean vector, vector and is also known as a fault-plane solution. Focal mechanisms are derived from a solution of the moment tensor for the earthquake, which itself is estimated by an analysis of observed seismic waveforms. The focal mechanism can be derived from observing the pattern of "first motions", whether the first arriving P waves break up or down. This method was used before waveforms were recorded and analysed digitally, and this method is still used for earthquakes too small for easy moment tensor solution. Focal mechanisms are now mainly derived using semi-automatic analysis of the recorded waveforms. Moment tensor solutions The moment tensor solution is displayed gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Wave Magnitude
Body-waves consist of P waves that are the first to arrive (see seismogram), or S waves, or reflections of either. Body-waves travel through rock directly. mB scale The original "body-wave magnitude" – mB or mB (uppercase "B") – was developed by and to overcome the distance and magnitude limitations of the scale inherent in the use of surface waves. is based on the P- and S-waves, measured over a longer period, and does not saturate until around M 8. However, it is not sensitive to events smaller than about M 5.5. Use of as originally defined has been largely abandoned, now replaced by the standardized scale. mb scale The mb or mb scale (lowercase "m" and "b") is similar to , but uses only P-waves measured in the first few seconds on a specific model of short-period seismograph. It was introduced in the 1960s with the establishment of the World-Wide Standardized Seismograph Network (WWSSN); the short period improves detection of smaller events, and better discrimina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Wave Magnitude
The surface wave magnitude (M_s) scale is one of the Seismic scale#Magnitude scales, magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements of Rayleigh wave, Rayleigh surface waves that travel along the uppermost layers of the Earth. This magnitude scale is related to the local magnitude scale proposed by Charles Francis Richter in 1935, with modifications from both Richter and Beno Gutenberg throughout the 1940s and 1950s. It is currently used in People's Republic of China as a guobiao, national standard (GB 17740-1999) for categorising earthquakes. Recorded magnitudes of earthquakes through the mid 20th century, commonly Richter magnitude scale, attributed to Richter, could be either M_s or M_L. Definition The formula to calculate surface wave magnitude is: :M_s = \log_\left(\frac\right)_ + \sigma(\Delta)\,, where A is the maximum particle displacement in surface waves (vector sum of the two horizontal displacements) in micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Louis University
Saint Louis University (SLU) is a private university, private Society of Jesus, Jesuit research university in St. Louis, Missouri, United States. Founded in 1818 by Louis William Valentine DuBourg, it is the oldest university west of the Mississippi River and one of the oldest Association of Jesuit Colleges and Universities, Jesuit universities in the United States. The university is Higher education accreditation in the United States, accredited by the Higher Learning Commission. In the 2023–2024 academic year, SLU had an enrollment of 15,204 students. The student body included 8,502 undergraduate students and 6,702 graduate students that represent all 50 states and 96 countries. The university is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very High Spending and Doctorate Production". For more than 50 years, the university has maintained the Saint Louis University Madrid Campus in Spain. The Madrid campus wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glacial Lake
A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier. Formation Near the end of the last glacial period, roughly 10,000 years ago, glaciers began to retreat. A retreating glacier often left behind large deposits of ice in hollows between drumlins or hills. As the ice age ended, these melted to create lakes. These lakes are often surrounded by drumlins, along with other evidence of the glacier such as moraines, eskers and erosional features such as glacial striations, striations and chatter marks. These lakes are clearly visible in aerial photos of landforms in regions that were glaciated during the last ice age. The formation and characteristics of glacial lakes vary between location and can be classified into glacial erosion lake, ice-blocked lake, moraine-dammed lake, other glacial lake, supraglacial lake, and subglacial lake. Glacial lakes and chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
