Answers
Answer:
Botswana
Explanation:
Related Questions
Please answer fast
1. Explain why you think the ancient Romans and Greeks used mythology to tell the story of volcanoes.
2. What are rift volcanoes? How do they form? What are cinder cones?
3. Identify and describe pyroclastic rocks.
4. Identify the different types of volcanoes and describe their unique characteristics.
Answers
Answer:
The ancient Romans and Greeks likely used mythology to tell the story of volcanoes because it was a way for them to explain natural phenomena that they did not understand. In ancient times, people often attributed natural events to the actions of gods and other supernatural beings. By using mythology to tell the story of volcanoes, the Romans and Greeks were able to provide a narrative for why volcanoes erupted and how they were created.Rift volcanoes are a type of volcano that forms along a rift zone, which is a crack in the Earth's surface. They typically have a long, narrow shape and are formed when the Earth's crust stretches and thinning, allowing magma to rise to the surface and create a volcano. Cinder cones, on the other hand, are small, steep-sided volcanoes that are formed when lava is ejected from a single vent. They are made up of pyroclastic material, such as ash and cinders, which are blasted into the air and fall back to the ground, forming a cone-shaped volcano.Pyroclastic rocks are a type of rock that is formed from fragments of material that are blasted into the air by volcanic eruptions. These fragments can include ash, cinders, pumice, and other materials that are created when magma is violently expelled from a volcano. Pyroclastic rocks are commonly found near volcanoes and can provide important clues about the nature and history of volcanic eruptions.There are several different types of volcanoes, each with its own unique characteristics. Some of the most common types include shield volcanoes, which are broad, gently sloping volcanoes formed from basalt lava flows; stratovolcanoes, which are steep, cone-shaped volcanoes formed from alternating layers of lava and ash; and calderas, which are large, circular or oval-shaped depressions formed when the ground collapses following a volcanic eruption. Other types of volcanoes include cinder cones, lava domes, and submarine volcanoes, which are volcanoes that form beneath the ocean's surface.what tectonic setting is responsible for the folded mountains of pennsylvania and the high himalaya? group of answer choices hot-spot push-together subduction pull-apart push-together obd
Answers
Convergent plate boundary is responsible for the folded mountains of pennsylvania and the high himalaya.
What is Convergent plate boundary ?
An area where two plates converge is referred to as a convergent border.The borders of one or both colliding plates may bow up into mountain ranges as a result of the impact, or one plate may bend downward into a deep undersea trench.What are three convergent boundary examples?
Examples. The Himalayas are being created as a result of the collision of the Indian and Eurasian plates. The Aleutian Islands are the result of the northern portion of the Pacific Plate subducting beneath the NW North American Plate. The Andes were created by the subduction of the Nazca Plate beneath the South American Plate.To know more about Convergent plate,checkout this link:
https://brainly.com/question/18981564
#SPJ1
koppen's climate classification makes use of a 3 letter code. for example, the humid subtropical climate has the letter code of cfa. what do each of the letters reference?
Answers
Local vegetation is used by the Köppen climate classification system to categorize climate zones globally.
Group A of the Köppen climatic classifications describes a tropical climate with average monthly temperatures of at least 18 °C (64.4 °F) and heavy precipitation.
Group B: Climates with little precipitation that do not match the polar (EF or ET) criterion of no month with an average temperature higher than 10 degrees Celsius are described as arid (50 degrees Fahrenheit).
Group C includes temperate climates. Group D includes continental climates, where at least one month's average temperature is below zero and sites are required to have both a dry summer (Cs) and a dry winter (Wd) (Cw).
Group E: Alpine and polar climate
Learn more on Köppen climate classifications:
https://brainly.com/question/29806872
#SPJ4
water vapor is a greenhouse gas that may actually cool the earth's climate. this is because: a) water can be a gas, but it can also be present in the atmosphere as ice, snow, sleet, and hail. b) water vapor lowers earth's temperature by evaporative cooling. c) increased water vapor would increase cloudiness, which increases earth's albedo. d) increased water vapor would increase cloudiness, which decreases earth's albedo.
Answers
Answer:
d) increased water vapor would increase cloudiness, which decreases earth's albedo.
Explanation:
which reason most likely explains why farmers are no longer encouraged to plant kudzu to prevent soil erosion?
Answers
There are a few possible reasons why farmers may no longer be encouraged to plant kudzu to prevent soil erosion:
Invasive species: Kudzu is a fast-growing, invasive plant species native to Asia that was introduced to the United States in the late 1800s. It is known for its ability to quickly spread and overtake native vegetation, making it difficult to control. As a result, kudzu is often considered a nuisance and has been classified as a noxious weed in some areas. Its ability to outcompete native plants can also have negative impacts on local ecosystems and biodiversity.Alternative methods: There are many other methods that farmers can use to prevent soil erosion, such as terracing, contour plowing, cover cropping, and the use of erosion control blankets or mulch. These methods may be more effective or more sustainable than planting kudzu, and may be preferred by farmers for this reason.Public perception: Kudzu has a negative reputation in some areas, and its association with soil erosion may contribute to this negative perception. Some people may view kudzu as an invasive or undesirable plant and may be opposed to its use as a means of preventing soil erosion.It is likely that farmers are no longer encouraged to plant kudzu as a primary means of preventing soil erosion due to its potential negative impacts on the environment and its reputation as an invasive species.
To learn more about soil erosion:
https://brainly.com/question/28882665
#SPJ4
3. how do violent volcanic eruptions, like mt. pinatubo's cataclysmic eruption in 1991, rich in sulfur dioxide (so2) affect the stratospheric ozone shield?
Answers
Nearly 20 million tons of sulfur dioxide were created by Mount Pinatubo's eruptions in 1991, which resulted in a brief dip in global temperatures of about 1°F (0.5°C) between 1991 and 1993.
Mount Pinatubo in the Philippines, which erupted in 1991, caused a brief 0.5°C drop in world temperatures. Volcanoes have the ability to create "years without summer" and cool the Earth for more than 5 years by ejecting millions of tons of Sun-blocking particles into the sky while they are active.
For years, lahars from the volcano's major river systems have been spilling into the neighboring lowlands, which are densely populated.
The consequences on the climate in 1992–1993 included a surface cooling of up to 0.5–0.6°C in the Northern Hemisphere, which is similar to a hemispheric drop in net radiation of 4 watts per square meter, and a cooling of maybe as much as –0.4°C over huge parts of the Earth.
Because of the weight of the ash that had been wet with rain, the seismic trembling, and the strong winds, many roofs in the neighboring communities, including those at the two huge U.S. military bases Clark and Subic Bay, fell.
Learn more about mt. Pinatubo's eruption at
https://brainly.com/question/14137604?referrer=searchResults
#SPJ4
Which Pacific South American country had its democratically elected
government replaced by military leaders supported by the United States?
A. Chile
OB. Peru
OC. Ecuador
OD. Bolivia
Answers
Answer:
The correct answer is A. Chile. In 1973
Explanation:
The democratically elected government of Chile led by Salvador Allende was overthrown by a military coup supported by the United States. The new military government, led by General Augusto Pinochet, implemented harsh authoritarian policies and suppressed political opposition, leading to widespread human rights abuses.
molten lava pours from a volcano in hawaii. after a few hours, the liquid lava hardens into a shiny gray rock. which phase change has taken place?
Answers
Freezing phase has taken place when molten lava pours from a volcano and after a few hours, the liquid lava hardens into a shiny gray rock.
What substances make up lava?Crystals, volcanic glass, and bubbles make up the components of lava (volcanic gases). Magma starts to crystallize olivine and produce volcanic gas bubbles as it cools and approaches the surface. A mush of crystals, liquid, and bubbles make up the lava when it erupts.
Why does lava get so hot?Two main factors make lava popular: Deep under the Earth (approximately 100 km below the surface), when rocks melt to form magma, it is extremely hot due to pressure and radiogenic heating. The rock around the magma acts as a good insulator, preventing it from losing much heat as it rises to the surface.
To know more about Lava visit:
https://brainly.com/question/15393639
#SPJ4
a good research question should be focused. Which of these potential topics is well-focused rather than too broad?a. The dietary preferences of flying insectsb. The impact of global warming on monarch butterfly migrationc. Identifying North American butterflies and mothsd. Butterfly and caterpillar colors: their chemistry, structure, and purposee. The worldwide distribution of prehistoric insects
Answers
Focus is key to a successful research question. These possible subjects' coverage of the eating habits of flying insects is well-targeted rather than overly general.
The topic of flying insect food choices is narrowly focused.
Monarch butterfly migration and the effects of global warming is a quite vast subject.
Identification of butterflies and moths in North America is a vast issue of that includes several aspects of species evolution.
The chemistry, structure, and functions underlying the colors of the butterflies and caterpillars may span the whole chemical and structural spectrum.
A vast subject, the global distribution of ancient insects. Focus is key to a successful research question. These possible subjects' coverage of the eating habits of a flying insects is well-targeted rather than overly general.
Learn more about Focus here
https://brainly.com/question/17161852
#SPJ4
identify a negative effect of increasing pest populations in forests or agricultural areas.
Answers
Answer:
Pests would destroy the plant life and the environment they are taking place in.
Explanation:
because the damage to plants caused by competition from weeds and by other pests like viruses, bacteria, fungi, and insects. They could efficiently destroy crops like its nothing!
upward air motion that leads to the growth of cumulus clouds to tremendous heights is called a (an)
Answers
Answer:
Updraft
Explanation:
Updrafts usually occur when winds accumulate over hills and mountains, creating tremendous force in which most cumulus clouds form.
An example of updrafts that don't form cumulus clouds is a big gust of wind going over your umbrella, pushing it out of your grip with tremendous force.
what is the relief between the ship creek gauging station in the ne corner of the map (use nearest contour line) and vabm ship survey marker along the eastern edge of the map?
Answers
The relief between the ship creek gauging station in the NE corner of the map (use the nearest contour line) and the vibe ship survey marker along the eastern edge of the map: (1) The ratio scale of this map is 1:63360.
A survey is a process of collecting, analyzing, and decoding records from many people. Its objective is to determine insights approximately a set of people. A survey goes plenty deeper than a questionnaire and often includes multiple shapes of information series.
In research of human subjects, a survey is a list of questions aimed at extracting specific facts from a specific organization of human beings. Surveys can be carried out by means of smartphone, mail, thru the internet, and also at road corners or in department shops.
Learn more about survey here:
https://brainly.com/question/24553900
#SPJ4
how do erosion and deposition work together to form sand dunes? waves cause erosion along coastlines and deposit sand away from the shore. erosion occurs as surface water carri
Answers
Waves cause erosion along coastlines and deposit sand away from the shore. - Erosion occurs as surface water carries sediment and the sediment is deposited near oceans and lakes
Erosion is the action of surface processes (such as water flow or wind) that remove soil, rock, or dissolved material from one location on the Earth's crust and then transport it to another location where it is deposited. Erosion differs from weathering, which involves no movement. The removal of rock or soil as clastic sediment is called physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or dissolved substances may be transported only a few millimeters or thousands of kilometers.
Agents of erosion include rainfall; erosion of bedrock in rivers; coastal erosion by sea and waves; plucking glaciers, abrasion and abrasion; widespread flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes, such as landslides and debris flows. The rates at which such processes operate govern how quickly the surface is eroded. Physical erosion usually occurs most rapidly on steeply sloping surfaces, and the rate may also be sensitive to some climate-controlled properties, including the amount of water supplied (eg, some ice-related processes).
Learn more about erosion here
https://brainly.com/question/17905503
#SPJ4
the fact that a forested area can be used for timber, grazing, recreation, or wildlife conservation follows what principle?
Answers
According to question, the fact that a forested area can be used for timber, grazing, recreation, or wildlife conservation follows primarily preservation
the five most typical uses for land Residential, agricultural, recreational, transit, and commercial land use are the five main categories. While many choices impacting local projects are made at the municipal level, managing the different uses of property is done through collaborations involving state, federal, and municipal organizations.
land used for product manufacture, refining, mining, etc. land used for transportation, including highways, railroads, and airports. Residential real estate includes single-family residences as well as multiplex buildings.
To know more about primarily preservation visit :
https://brainly.com/question/17116267
#SPJ4
what is the main reason that the gravitational attraction between earth and the moon changes each day?
Answers
The Moon has an elliptical orbit is the main reason that the gravitational attraction between Earth and the Moon changes each day.
The Effect of Earth's Gravity and Moon's GravityEarth's gravity pulls the moon to the center of the earth, while the moon's gravitational force maintains the moon's position, resulting in a centrifugal force that makes the moon rotate on its axis and surround the earth so that it is not attracted to the earth's center of gravity or stays in its orbit.
The influence of the gravitational force of the earth and the moon is the tides of the sea. The moon's gravitational force pulls seawater toward the moon, affecting wave height and sea level. Because the moon revolves around the earth, there will be times when one side of the earth is closer to the moon. The part that is close to the moon will experience high tide, while the other part that is not close to the moon will experience low tide. The tides are also related to the phases of the moon. Usually, sea water will experience high tides during the full moon.
Learn more about gravitational attraction at https://brainly.com/question/21274057.
#SPJ4
what is the main difference between the out-of-africa hypothesis and the multiregional continuity hypothesis?
Answers
"The 'Out of Africa' theory believed that humans migrated from Africa to Eurasia and replaced all Homo erectus, but after leaving Africa, Homo erectus slowly spread to various continents of the world." This is in contrast to the "multi-regional continuity theory" that claims to have moved evolved.
Eurasia is the largest continent on earth and includes all of Europe and Asia. It extends mainly in the northern and eastern hemispheres, from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago and the Russian Far East in the east.
This term is a portmanteau of Europe and Asia. The physical union of Europe and Asia constitutes geological Eurasia, but the land boundary between these two continents is not universally agreed upon.
A supercontinent consisting of Europe and Asia. largest land in the world. Russia, Great Britain, China, France, Germany and Iran are examples of Eurasian countries.
Learn more about Eurasia https://brainly.com/question/312763
#SPJ4
The prevailing winds in the northern sub-tropical region (0-30 N) tend to blow in
which direction?
a. From the northeast to the west (the trade winds)
b. From the west to the east
c. No change, they are constant
Answers
Answer:b. From the west to the east
Explanation:
1. occasionally, a layer of cool air forms under a layer of warmer air in the troposphere. this change from the normal temperature profile in the troposphere is called a
Answers
On occasion, in the troposphere, a layer of cool air develops beneath a layer of warmer air. A thermal inversion is the name given to this deviation from the typical temperature profile in the troposphere.
When the warmer layer of air is above the cold layer, which is not typically the case, this is known as a thermal inversion or change in the location of the air layer. It occurs when the typical temperature gradient changes, or when the gradient is inverted. These thermal inversions can happen in oceanic regions where there is significant upwelling close to the coast. When the sun's radiation is lower than the earth's radiation, as it is at night, thermal inversion also happens. These inversions have significant implications, particularly for the air quality in polluted environments like cities. Wintertime inversions are the strongest and can be hazardous because of the low air quality, as indicated by the AQI (Air Quality Index). The risk of breathing in bad air, or worse air, increases as the AQI index rises.
To learn more about Thermal Inversion:
https://brainly.com/question/12981849
#SPJ4
50 POINTS WILL GIVE BRAINLIEST Before becoming democracies in the late 20th century, most Atlantic South
American countries had which form of government?
O A. Oligarchy
OB. Dictatorship
OC. Theocracy
OD. Monarchy
Answers
Which branch checks officials appointed by the president can be forced to answer questions from the congress
Answers
Senate branch checks officials appointed by the president can be forced to answer questions from the congress.
The Executive branch is viewed as headed by the president. The ability of one branch of government to limit the power of others is referred to as a "check" in government.Congress is a branch of the legislature. The president can stop the Congress from passing a law proposal because he or she has the right to veto it.
Justices of the Supreme Court are members of the judicial branch. By having the option to pick the Judges, the president can impact individuals that will go with the choice on the off chance that individuals from government authorities participated in a contention.
DISCLAIMER: The question is incomplete.
Which branch checks officials appointed by the president can be forced to answer questions from the congress?
-Senate
-Prime minister
-Chief Executive
To learn more about president
https://brainly.com/question/19520900
#SPJ1
end of semester test: michigan world history and geography b what was the impact on religion of the scientific discoverieces
Answers
The impact on religion of the scientific revolution is as the church's influence declined in Europe, science started to shift toward a secular perspective.
What is the impact religion to the scientific revolution?Science shifted from being dependent on faith to being more fact- and logic-based by excluding religion from the discussion. This change allowed for a wealth of new scientific understandings of the natural world. Science has no limits in its understanding of the natural world when religion was not a hindrance. The series of scientific advancements in the seventeenth century altered the power dynamics in the West and challenged the church's dominance as the most important institution by casting doubt on the veracity of Christian ideas and presenting evidence that was in direct opposition to them.
Learn more about scientific revolution: https://brainly.com/question/14231443
#SPJ4
FILL IN THE BLANK. the absorption of longwave radiation in the atmosphere is popularly called ________.
Answers
Answer:
GREENHOUSE EFFECT
Explanation:
Some longwave radiation is absorbed by carbon dioxide, water vapor, methane, CFCs (chlorofluorcarbons), and other gases in
the lower atmosphere and is then reradiated to Earth, thereby delaying energy loss to space. This process is termed greenhouse effect.
i hope this helps
correct answer is :- Green house effect
The term "greenhouse effect" refers to the process through which solar energy is absorbed by greenhouse gases rather than being reflected back into space. This keeps the earth's surface from freezing by insulating it.
But the earth's temperature has significantly risen as a result of the rising concentrations of greenhouse gases. A number of drastic impacts have resulted from this.
The gases known as greenhouse gases are those that absorb infrared rays and produce the greenhouse effect. Examples include carbon dioxide and chlorofluorocarbons.
know more about greenhouse gases here
https://brainly.com/question/28804686#
#SPJ4
Earth is closer to the Sun in January than in July. Therefore, in accord with Kepler's second law, (a) Earth travels faster in its orbit around the Sun in July than in January. (b) Earth travels faster in its orbit around the Sun in January than in July. (c) it is summer in January and winter in July.
Answers
Answer:
option (b)Earth travels faster in its orbit around the Sun in January than in July.
Explanation:
KEPLER ’S SECOND LAW DESCRIBES THE WAY AN OBJECT ’S SPEED VARIES on ITS ORBIT
A earth’s orbital speed changes, depending on how far it's from the Sun. The closer a earth is to the Sun, the stronger the Sun’s gravitational pull on it, and the briskly the earth moves. The further it's from the Sun, the weaker the Sun’s gravitational pull, and the slower it moves in its route.
To know more about
https://brainly.com/question/18362371
During the generativity versus stagnation phase, adults feel a need to give back to society, often by raising children.T/F
Answers
Adults sense a need to contribute back to society during the generativity versus stagnation period, frequently through raising children.
In general, adults who want to contribute something worthwhile to the next generation are happier with their lives. According to Erik Erikson, the seventh stage of psychosocial development is a contest between generativeness and stagnation. Adults in this stage frequently parent, give back to the community, or effect other positive changes in an effort to create or nourish things. Low-quality connections: Stasis may be the outcome of low-quality social interactions because the growth of generativity is connected to positive relationships with others. As people age, this may become a concern because social connections are crucial for aging healthily. When midlife transitions occur, a 40-year-old might generally reflect on his life and achievements and engage in introspection. They would also consider what needed to be done next in the future. It offers a success or failure to this transition in generativity versus stagnation.
Learn more about generativity here :
https://brainly.com/question/10518212
#SPJ4
how was china's experence with european imperilism similar or differemt from that of africa and india
Answers
Answer:
Imperialism in India was very similar to imperialism in Africa. In a photo, an Indian servant is giving a British man a pedicure while another reflects the sun onto him. Like in Africa, the British that imperialized India were very forceful and treated the Indians like their servants.
Explanation:
Prezi Website
(please mark as brainliest)
scientists claim that south america was part of a large landmass called gondwana, which included antarctica and australia. which law or theory supports the claim?
Answers
The law or theory supports the claim of scientists that claim that south america was part of a large landmass called gondwana, which included antarctica and australia is The continental drift law
Law of continental driftContinental drift is one of the earliest theories proposed by geologists for how continents might shift through time. The science of plate tectonics has now supplanted the theory of continental drift. The idea of continental drift is most directly related to the scientist Alfred Wegener. In the early 20th century, Wegener published a paper describing his theory that the continents were "drifting" over the surface of the Earth, periodically crashing through oceans and into one another.
Gondwanaland, a vast continent that includes Antarctica, South America, Africa, India, and Australia, was created about 200 million years ago. There was no ice sheet, and trees and huge animals were in plenty.
To know more about continental drift refer to:
brainly.com/question/974409
#SPJ4
What processes would likely stop if Earth’s interior cooled so much that the tectonic plates stopped moving?
melting and metamorphism
metamorphism and pressure
melting and erosion
erosion and deposition
pls help
Answers
Answer: I believe the most logical answer is erosion and deposition.
Explanation:
Please help me
Thank you
Answers
Gangs of men connected to Thomas Edison would knock on doors of independent film studio and threaten hem over patents. This shrewd action caused this era to me known as Patent Wars era.
What is Patent Wars?A "fight" to gain patents for legal action, either offensively or defensively, is known as a "patent war" between businesses or individuals. The biggest technology and software companies in the world are engaged in ongoing patent warfare.
The innovative study in the documentary on patent wars reveals who benefits from intellectual property and who is responsible for its economic and societal repercussions.
However On October 17, 1888, Thomas Edison submitted a proviso to the Patents Office in an effort to safeguard his future innovations. In it, he outlined his plans for a machine that would "do for the vision what the phonograph does for the ear"—record and reproduce moving objects.
Therefore the era referred as known as Patent Wars Era.
Learn more about Patent Wars refer:
https://brainly.com/question/8932644
#SPJ1
Why did battles occur between natives and settlers
Answers
One of the key reasons for battles between the Native Americans and Settlers is as follows
Native Americans rejected and fought back against the colonists' attempts to transform them. The conflict quickly erupted between the two groups as a result of their failure to adopt European culture, which infuriated the colonists.
The English colonists' tense interactions with the Native Americans, who had resided in the region for several thousand years, in Jamestown, Virginia, in 1607, led off the Indian Wars. Hundreds of various tribes were made up of millions of indigenous people who had colonised North America at the time. However, a series of conflicts between American Indians and European settlers known as the Indian Wars occurred between 1622 and the late 19th century, primarily over land ownership.
Read more about Native Americans from:
https://brainly.com/question/13794240
Explanation: Pour comprendre pourquoi des batailles ont eu lieu entre les autochtones et les colons, nous devons comprendre le contexte historique et politique de cette situation.
Tout d’abord, il faut comprendre que les autochtones représentaient une population majoritairement indigène qui vivaient dans les régions où les colons européens sont arrivés. Ils vivaient de façon autonome et indépendante, et avaient leurs propres systèmes de gouvernement et de croyances.
D'un autre côté, les colons européens étaient motivés par l'idée de coloniser des terres et de s'enrichir. Ils croyaient que ces terres leur appartenaient et que les autochtones n'avaient pas le droit d'y vivre et de les exploiter.
En conséquence, les colons ont essayé de prendre le contrôle des terres occupées par les autochtones, ce qui a conduit à des conflits violents entre les deux parties. Les autochtones ont été forcés de fuir et de se défendre contre les colons. Les colons ont également essayé d’imposer leur culture et leurs croyances aux autochtones et de les assimiler à leurs propres cultures.
En conclusion, les batailles entre les autochtones et les colons ont eu lieu en raison de l'oppression des colons et de leur détermination à prendre le contrôle des terres des autochtones et à imposer leur culture et leurs croyances.
The ue of the Euro and the removal of trade barrier in the European Union ha created what?
Answers
Euro peans throughout the middle ages started to trade often in small markets and at the bigger, less frequent fairs held in towns and capitals.
Both of them were established with the consent of the local church leaders and council members, who in turn promoted a developing trade-based economy. In the European Union (EU), all border restrictions on the movement of capital, labor, and capital products had been lifted by 1993. To ensure that there are no trade obstacles, even items like consumer protection regulations and the sorts of connectors needed to plug in appliances have been standardized. A trade pact was reached by all of the members of the European Union as well as a number of non-EU countries, creating the European Single Market. As the Single Market developed, it became A worldwide economic behemoth that could compete more successfully than its constituent countries alone. The EU negotiates contracts on behalf of its member nations and is in charge of their trade policies. In international trade discussions, the EU's collective voice is more influential than the voices of its individual members. To negotiate trade agreements, the EU actively works with nations or regional organizations.
Learn more about Euro here :
https://brainly.com/question/29791516
#SPJ4