Proxy Data Definition
What Are “Proxy” Data?
In paleoclimatology, or the study of past climates, scientists use what is known as proxy data to reconstruct past climate conditions. These proxy data are preserved physical characteristics of the environment that can stand in for direct measurements. Paleoclimatologists gather proxy data from natural recorders of climate variability such as tree rings, ice cores, fossil pollen, ocean sediments, corals and historical data. By analyzing records taken from these and other proxy sources, scientists can extend our understanding of climate far beyond the instrumental record.
Historical Data
Historical documents, which are one type of proxy data, can contain a wealth of information about past climates. Observations of weather and climate conditions can be found in ship and farmers’ logs, travelers’ diaries, newspaper accounts, and other written records. When properly evaluated, historical documents can yield both qualitative and quantitative information about past climate. For example, scientists used historical grape harvest dates to reconstruct summer temperatures, between April and September, in Paris from 1370 to 1879.
Corals
Another type of proxy data, corals build their hard skeletons from calcium carbonate—a mineral extracted from seawater. The carbonate contains isotopes of oxygen as well as trace metals that can be used to determine the temperature of the water in which the coral grew. Scientists can then use these temperature recordings to reconstruct the climate when the coral lived. See Picture Climate: How We Can Learn from Corals to learn more about how scientists determine climate conditions from these beautiful ecosystems.
Pollen
All flowering plants produce pollen grains, which are another type of proxy data. Scientists can use the distinctive shapes of pollen grains to identify the type of plant from which they came. Since pollen grains are well preserved in the sediment layers in the bottom of a pond, lake, or ocean, an analysis of the pollen grains in each layer tells scientists what kinds of plants were growing at the time the sediment was deposited. Scientists can then make inferences about the climate of the area based on the types of plants found in each layer. See Picture Climate: How Pollen Tells Us About Climate to learn more about how scientists learn about climate from these tiny grains.
Ice Cores
Located high in the mountains and near the poles, ice—another type of proxy data—has accumulated from snowfall over many millennia. Scientists drill through the deep ice to collect ice cores, which often have distinct layers in them. These layers contain dust, air bubbles, or isotopes of oxygen, differing from year to year based on the surrounding environment, that can be used to interpret the past climate of an area. Ice cores can tell scientists about temperature, precipitation, atmospheric composition, volcanic activity, and even wind patterns. See Picture Climate: What Can We Learn from Ice? to learn more about how scientists study climate using ice cores.
Tree Rings
Trees and their unique rings also serve as proxy data. Because climate conditions influence tree growth, patterns in tree-ring widths, density, and isotopic composition reflect variations in climate. In temperate regions where there is a distinct growing season, trees generally produce one ring a year, recording the climate conditions each year. Trees can grow to be hundreds to thousands of years old and can contain annual records of climate for centuries to millennia. See Picture Climate: How Can We Learn from Tree Rings? to learn more about how scientists study climate using tree rings.
Ocean and Lake Sediments
Another type of proxy data can be found on the floors of the Earth’s oceans and lakes. Billions of tons of sediment accumulate in ocean and lake basins each year, providing a vast amount of information about the environment in them. Scientists drill cores of the sediments from the basin floors and examine their contents, which include tiny fossils and chemicals, to interpret past climates.
These are just a few examples of the environmental recorders scientists can use to learn about ancient climates. Learn more about the science behind the study of ancient climates at What is Paleoclimatology? and How Do Scientists Study Ancient Climates? Or visit NCDC’s Paleoclimatology Data page to access the Center’s proxy data holdings.
Paleo Proxy Data: What Is It? | IEDRO
September 29, 2010
By Martina M. Dewey
A paleoclimatologist’s work is science focused on the climate of past ages. Proxy data is data that paleoclimatologists gather from natural recorders of climate variability, e. g., tree rings, ice cores, fossil pollen, ocean sediments, coral and historical data. By analyzing records taken from these and other proxy sources, scientists can extend our understanding of climate far beyond the 140-year instrumental record.
Widely Used Paleo Proxy Data
Historical Data: Historical documents contain a treasure of information about the climates of the past. Observations of weather and climate conditions can be found in places such as farmers and ships logs and newspaper accounts. Other written records may contain information, that when properly evaluated, can both provide qualitative and quantitative data about past climates.
Corals: Corals build their hard skeletons from calcium carbonate—a mineral extracted from sea water. The carbon contains isotopes and trace metals that can be used to tell the conditions of the water in which coral grows, such as temperature. The use of temperature recordings can be vital in the reconstruction of the conditions in which the coral lived.
For more information on coral visit: Fossil Pollen: All plants that flower produce pollen. The pollen grains that each plant produces can be used to identify the type of plant from which it came. This is deduced from the unique shape of the grain. Pollen grains become preserved in sediments over time, usually in the bottom of lakes, oceans or ponds. When scientists analyze the pollen grains they are able to tell what types of plants were growing at a specific time. Conclusions can then be made about the climate due to the types of plants found within each layer.
More information on fossil pollen can be found at the United States Geological Survey website. Their homepage is: They also specifically have a page dedicated to fossil pollen titled “Fossil Groups- Spores and Pollens” that can be located at Tree Rings: The growth of a tree is influenced significantly by climate. Tree ring widths, density of the trees, and isotopic composition are a reflection on the climate a tree is in. For example in a balmy climate a tree usually produces only one ring a year thus providing a record of climatic conditions each given year. Trees can grow to be hundreds or even thousands of years old and hold records of climate for centuries to millennia.
The University of Arizona has a Laboratory for Tree Ring research. You can access their website here: The Ultimate Tree Ring Webpage for the University of Tennessee can be found at:. The webpage, compiled by Henri D. Grissino-Mayer of the University of Tennessee at Knoxville, focuses on the science of Dendochronology (carbon dating of remains).
Ice Cores: Ice is located in polar ice caps and high in mountains and has accumulated due to snowfall over many millions of years. Climatologists dig through the ice with drills to collect ice cores. These cores contain many things such as dust, air bubbles and oxygen isotopes. Expert scan use what they have collected to determine the past climate of an area
Ocean and Lake Sediments: There are billions of tons of sediments that gather in lakes and oceans each and every year. Scientists and experts drill cores of sediment from the basin floors. The sediment on the floors of lakes and oceans contain tiny fossils as well as chemicals that are used to explain past climates.
For information on ocean drilling please visit the website of ODP at Texas A & M University in College Station, Texas at:
Criminal Investigation Chapter 5 Flashcards | Quizlet
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Upgrade to remove adsOnly $47. 88/yearSocial ScienceLawCriminal LawSTUDYFlashcardsLearnWriteSpellTestPLAYMatchGravityTerms in this set (42)Forensic ScienceApplication of scientific processes to solve legal problems most notably within the context of the criminal justice DataThe evidence analyzed by forensic scientists to uncover the relationship between people, places, and objects. EvidenceData on which judgment or conclusion may be EvidenceThe original evidence or highest available degree of proof that can be ysical EvidenceAnything real – that is, which has substance – that helps establish the facts of the EvidenceEstablishes proof of a fact without any other direct EvidenceMerely tends to incriminate a person – for instance, a suspect’s footprint found at the crime rcumstantial EvidenceEvidence from which inferences are EvidenceA subset of direct evidence. Extremely small items, such as hair or Facie EvidenceEvidence established by sociative EvidenceLinks a suspect with a Delicti EvidenceEstablishes that a crime has been Delicti”Body of the crime” – In a murder case is not the dead body but the fact that a death resulted from a criminal obative EvidenceVital to the investigation or prosecution of a case, tending to prove or actually proving guilt or terial EvidenceForms a substantive part of the case or has a legitimate and effective influence on the decision of the levant EvidenceApplies to the matt in mpetent EvidenceHas been properly collected, identified, filed and continuously ntaminationPost crime transfer of tegrity of EvidenceThe requirement that any item introduced in court must be in the same condition as when it was found at the crime of Evidence/Chain of CustodyDocumentation of what has happened to the evidence from the time it was discovered until it is needed in court, including every person who has had custody of the evidence and andard of ComparisonAn object, measure or model with which evidence is compared to determine whether both came from the same items of evidence to touch one another and thus exchange matter. Daubert StandardTwo pronged test – Expert’s testimony be both Reliable and ometricsThe statistical study of biological data and means of positively identify an individual by measuring the person’s unique physical or behavioral CharacteristicsThe features that place an item into a specific dividua CharacteristicsThe features that distinguish one item from another of the same FingerprintsImpressions transfered to a surface, either by sweat on the ridges of the fingers or because the fingers carry residue of oil, dirt, blood or other substances. Can be developed through powders or sible FingerprintsMade when fingers are dirty or stained. Can be dusted and astic FingerprintsOne from of visible print, are impressions led in soft substances such as putty, grease, tar, butter or soft soap. Photographed, not dusted. Elimination PrintsPrints of persons with reason to be at the kless FingerprintScanned and converted latent fingerprints that are stored in a database for rapid vanced Fingerprint Information Technology – (AFIT)An integrated system that can also incorporate additional biometric data such as latent palmprints and facial recognition technology. VoiceprintA graphic record made by a sound spectrograph of the energy patterns emitted by speech. DNAOrganic substance contained in a cell’s ProfilingUses material from which chromosomes are made to identify individuals make an MarkAn impression left by a tool on a llisticsStudy of the dynamics of projectiles, from propulsion through flight to impact – aka study of the functioning of reInside portion of a weapon’s barrel, which is surrounded by raised ridges called lands and recessed areas called grooves. RiflingThe spiral pattern cut down the entire length of the firearm barrel that grips and spins the bullet as it passes through the bore, providing greater projectile control and liberThe diameter of the bore as measured between lands as well as the size of the bullet intended for use with a specific riationsScratches, from the rifling, which provide valuable comparison evidence on recovered with similar termsChapter 5: Forensics/Physical Evidence50 termsjoselyn82CJ 3 chapter 5 vocab42 termsDaniel_Guzman17Chapter 5 CJ vocab33 termsNoahChev777Chapter 5: Forensics/Physical Evidence38 termsnschafer1Other sets by this creatorIBOLC FINAL29 termschristian_nillIBOLC RED PHASE EXAM34 termschristian_nillPhil 252 final42 termschristian_nillPHIL 252 Final43 termschristian_nillOther Quizlet setsCh 413 termsyattayahadvance evidence 133 termszoraa20 types of evidence21 termsBrockShoffner69HIM LAW Chap 5-671 termsN7Kami
Frequently Asked Questions about proxy data definition
What is proxy data in data science?
Proxy data is data that paleoclimatologists gather from natural recorders of climate variability, e.g., tree rings, ice cores, fossil pollen, ocean sediments, coral and historical data. … The pollen grains that each plant produces can be used to identify the type of plant from which it came.Sep 29, 2010
What is proxy data in forensic science?
Proxy Data. The evidence analyzed by forensic scientists to uncover the relationship between people, places, and objects. Evidence. Data on which judgment or conclusion may be based.
How accurate is proxy data?
Overall, any individual proxy is not a reliable indicator. It’s the combination of multiple proxies that provides a clearer picture. If we were to only look at tree-rings, we could not possibly trust on them as a reliable source, since they have known problems.May 6, 2014
